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| [[Image:Alpha-Amanitin–RNA polymerase II complex 1K83.png|thumb|300px|right|RNA Polymerase from ''[[Saccharomyces cerevisiae]]'' complexed with α-amanitin (in red). Despite the use of the term "polymerase," RNA Polymerases are classified as a form of nucleotidyl transferase.<ref>{{cite web|title=EC 2.7.7 Nucleotidyltransferases|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/7/7/|work=Enzyme Nomenclature. Reccomendations|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=14 November 2013}}</ref>]]
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| In [[biochemistry]], '''transferase''' is the general name for the class of enzymes that enact the transfer of specific [[functional group]]s (e.g. a methyl or glycosyl group) from one [[molecule]] (called the donor) to another (called the acceptor).<ref>{{cite web|title=Transferase|url=http://ghr.nlm.nih.gov/glossary=transferase|work=Genetics Home Reference|publisher=National Institute of Health|accessdate=4 November 2013}}</ref> They are involved in hundreds of different [[Molecular pathway|biochemical pathways]] throughout [[biology]], and are integral to some of life’s most important processes.
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| Transferases are involved in a myriad of reactions in the cell. Some examples of these reactions include the activity of [[Coenzyme A|CoA]] transferase, which transfers thiol esters,<ref name=Moore>{{cite journal | author = Moore SA, Jencks WP | title = Model reactions for CoA transferase involving thiol transfer. Anhydride formation from thiol esters and carboxylic acids | journal = J. Biol. Chem. | volume = 257 | issue = 18 | pages = 10882–92 |date=September 1982 | pmid = 6955307 | doi = }}</ref> the action of [[N-acetyltransferase]], which is part of the pathway that metabolizes tryptophan,<ref>{{cite web|last=Wishart|first=David|title=Tryptophan Metabolism|url=http://pathman.smpdb.ca/pathways/SMP00063/pathway|work=Small Molecule Pathway Database|publisher=Department of Computing Science and Biological Sciences, University of Alberta|accessdate=4 November 2013}}</ref> and also includes the regulation of [[pyruvate dehydrogenase|PDH]], which converts [[pyruvate]] to [[Acetyl CoA]].<ref>{{cite journal|last=Herbst|first=EA|coauthors=Macpherson, RE; Leblanc, PJ; Roy, BD; Jeoung, NH; Harris, RA; Peters, SJ|title=Pyruvate Dehydrogenase Kinase-4 Contributes to the Recirculation of Gluconeogenic Precursors During Post-Exercise Glycogen Recovery.|journal=American journal of physiology. Regulatory, integrative and comparative physiology|date=Dec 4, 2013|pmid=24305065|doi=10.1152/ajpregu.00150.2013|volume=306|issue=2|pages=R102-7}}</ref> Transferases are also utilized during translation. In this case, an amino acid chain is the functional group transferred by a [[Peptidyl transferase]]. The transfer involves the removal of the growing [[amino acid]] chain from the [[transfer RNA|tRNA]] molecule in the [[A-site]] of the [[ribosome]] and its subsequent addition to the amino acid attached to the tRNA in the [[P-site]].<ref>Watson, James D. Molecular Biology of the Gene. Upper Saddle River, NJ: Pearson, 2013. Print.</ref>
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| Mechanistically, an enzyme that catalyzed the following reaction would be a transferase:
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| <math> Xgroup + Y \xrightarrow[transferase]{} X + Ygroup </math>
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| In the above reaction, X would be the donor, and Y would be the acceptor.<ref>{{cite journal | author = Boyce S, Tipton KF | title = Enzyme Classification and Nomenclature | journal = eLS | year = 2005 | url = http://onlinelibrary.wiley.com/doi/10.1038/npg.els.0003893/abstract | doi=10.1038/npg.els.0003893}}</ref> "Group" would be the functional group transferred as a result of transferase activity. The donor is often a [[coenzyme]].
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| ==History==
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| Some of the most important discoveries relating to transferases occurred as early as the 1930s. Earliest discoveries of transferase activity occurred in other classifications of [[enzyme]]s, including [[Beta-galactosidase]], [[protease]], and acid/base [[phosphatase]]. Prior to the realization that individual enzymes were capable of such a task, it was believed that two or more enzymes enacted functional group transfers.<ref name="pmid13072573">{{cite journal | author = Morton RK | title = Transferase activity of hydrolytic enzymes | journal = Nature | volume = 172 | issue = 4367 | pages = 65–8 |date=July 1953 | pmid = 13072573 | doi = | url = }}</ref>
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| [[Image:Dopamine degradation.svg|thumb|right|Biodegradation of dopamine via catechol-O-methyltransferase (along with other enzymes). The mechanism for dopamine degradation led to the Nobel Prize in Physiology or Medicine in 1970.]]
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| [[Transamination]], or the transfer of an [[amine]] (or NH<sub>2</sub>) group from an amino acid to a [[keto acid]] by an [[aminotransferase]] (also known as a "transaminase"), was first noted in 1930 by D. M. Needham, after observing the disappearance of [[glutamic acid]] added to pigeon breast muscle.<ref name="pmid16747057">{{cite journal | author = Cohen PP | title = Transamination in pigeon breast muscle | journal = Biochem. J. | volume = 33 | issue = 9 | pages = 1478–87 |date=September 1939 | pmid = 16747057 | pmc = 1264599 | doi = }}</ref> This observance was later verified by the discovery of its reaction mechanism by Braunstein and Kritzmann in 1937.<ref>{{cite journal | author = Snell EE, Jenkins WT | title = The mechanism of the transamination reaction|journal=Journal of Cellular and Comparative Physiology |date=December 1959 | volume = 54 | issue = S1 | pages = 161–177 | doi = 10.1002/jcp.1030540413 }}</ref> Their analysis showed that this reversible reaction could be applied to other tissues.<ref>{{cite journal|last= Braunstein AE, Kritzmann MG | title = Formation and Breakdown of Amino-acids by Inter-molecular Transfer of the Amino Group | journal = Nature | year = 1937 | volume = 140 | issue = 3542 | pages = 503–504 | doi = 10.1038/140503b0 }}</ref> This assertion was validated by [[Rudolf Schoenheimer]]'s work with [[radioisotope]]s as [[Isotopic labelling|tracers]] in 1937.<ref>{{cite book|last=Schoenheimer|first=Rudolf|title=The Dynamic State of Body Constituents|year=1949|publisher=Hafner Publishing Co Ltd|isbn=0028518004}}</ref><ref name="pmid1941176">{{cite journal | author = Guggenheim KY | title = Rudolf Schoenheimer and the concept of the dynamic state of body constituents | journal = J. Nutr. | volume = 121 | issue = 11 | pages = 1701–4 |date=November 1991 | pmid = 1941176 | doi = }}</ref> This in turn would pave the way for the possibility that similar transfers were a primary means of producing most amino acids via amino transfer.<ref name="pmid14780123">{{cite journal | author = Hird , Rowsell | title = Additional transaminations by insoluble particle preparations of rat liver | journal = Nature | volume = 166 | issue = 4221 | pages = 517–8 |date=September 1950 | pmid = 14780123 | doi = 10.1038/166517a0 }}</ref>
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| Another such example of early transferase research and later reclassification involved the discovery of uridyl transferase. In 1953, the enzyme [[UDP-glucose pyrophosphorylase]] was shown to be a transferase, when it was found that it could reversibly produce [[uridine triphosphate|UTP]] and [[glucose 1-phosphate|G1P]] from [[Uridine diphosphate glucose|UDP-glucose]] and an organic [[pyrophosphate]].<ref name="pmid13111246">{{cite journal | author = Munch-Petersen A, Kalcar HM, Cutolo E, Smith EE | title = Uridyl transferases and the formation of uridine triphosphate; enzymic production of uridine triphosphate: uridine diphosphoglucose pyrophosphorolysis | journal = Nature | volume = 172 | issue = 4388 | pages = 1036–7 |date=December 1953 | pmid = 13111246 | doi = }}</ref>
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| Another example of historical significance relating to transferase is the discovery of the mechanism of [[catecholamine]] breakdown by [[catechol-O-methyltransferase]]. This discovery was a large part of the reason for [[Julius Axelrod|Julius Axelrod’s]] 1970 [[Nobel Prize in Physiology or Medicine]] (shared with [[Bernard Katz|Sir Bernard Katz]] and [[Ulf von Euler]]).<ref>{{cite web|title=Physiology or Medicine 1970 - Press Release|url=http://www.nobelprize.org/nobel_prizes/medicine/laureates/1970/press.html|work=Nobelprize.org|publisher=Nobel Media AB|accessdate=5 November 2013}}</ref>
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| Classification of transferases continues to this day, with new ones being discovered frequently.<ref>{{cite journal|last=Lambalot|first=RH|coauthors=Gehring, AM; Flugel, RS; Zuber, P; LaCelle, M; Marahiel, MA; Reid, R; Khosla, C; Walsh, CT|title=A new enzyme superfamily - the phosphopantetheinyl transferases.|journal=Chemistry & biology|date=November 1996|volume=3|issue=11|pages=923–36|pmid=8939709}}</ref><ref>{{cite journal|last=Wongtrakul|first=J|coauthors=Pongjaroenkit, S; Leelapat, P; Nachaiwieng, W; Prapanthadara, LA; Ketterman, AJ|title=Expression and characterization of three new glutathione transferases, an epsilon (AcGSTE2-2), omega (AcGSTO1-1), and theta (AcGSTT1-1) from Anopheles cracens (Diptera: Culicidae), a major Thai malaria vector.|journal=Journal of medical entomology|date=March 2010|volume=47|issue=2|pages=162–71|pmid=20380296}}</ref> An example of this is Pipe, a sulfotransferase involved in the dorsal-ventral patterning of ''[[Drosophilia]]''.<ref>{{cite journal|last=Sen|first=J|coauthors=Goltz, JS; Stevens, L; Stein, D|title=Spatially restricted expression of pipe in the Drosophila egg chamber defines embryonic dorsal-ventral polarity.|journal=Cell|date=Nov 13, 1998|volume=95|issue=4|pages=471–81|pmid=9827800}}</ref> Initially, the exact mechanism of Pipe was unknown, due to a lack of information on its substrate.<ref>{{cite journal|last=Moussian|first=B|coauthors=Roth, S|title=Dorsoventral axis formation in the Drosophila embryo--shaping and transducing a morphogen gradient.|journal=Current biology : CB|date=Nov 8, 2005|volume=15|issue=21|pages=R887-99|pmid=16271864|doi=10.1016/j.cub.2005.10.026}}</ref> Research into Pipe's catalytic activity eliminated the likelihood of it being a heparan sulfate glycosaminoglycan.<ref>{{cite journal|last=Zhu|first=X|coauthors=Sen, J; Stevens, L; Goltz, JS; Stein, D|title=Drosophila pipe protein activity in the ovary and the embryonic salivary gland does not require heparan sulfate glycosaminoglycans.|journal=Development (Cambridge, England)|date=September 2005|volume=132|issue=17|pages=3813–22|pmid=16049108|doi=10.1242/dev.01962}}</ref> Further research has shown that Pipe targets the ovarian structures for sulfation.<ref>{{cite journal|last=Zhang|first=Z|coauthors=Stevens, LM; Stein, D|title=Sulfation of eggshell components by Pipe defines dorsal-ventral polarity in the Drosophila embryo.|journal=Current biology : CB|date=Jul 28, 2009|volume=19|issue=14|pages=1200–5|pmid=19540119|doi=10.1016/j.cub.2009.05.050}}</ref> Pipe is currently classified as a ''Drosophilia'' [[heparan sulfate 2-O-sulfotransferase]].<ref>{{cite journal|last=Xu|first=D|coauthors=Song, D; Pedersen, LC; Liu, J|title=Mutational study of heparan sulfate 2-O-sulfotransferase and chondroitin sulfate 2-O-sulfotransferase.|journal=The Journal of Biological Chemistry|date=Mar 16, 2007|volume=282|issue=11|pages=8356–67|pmid=17227754|doi=10.1074/jbc.M608062200}}</ref>
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| ==Nomenclature==
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| [[Systematic name]]s of transferases are constructed in the form of "donor:acceptor grouptransferase."<ref name="EC2 Intro">{{cite web|title=EC 2 Introduction|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/intro.html|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=5 November 2013}}</ref> For example, methylamine:L-glutamate N-methyltransferase would be the standard naming convention for the transferase [[methylamine-glutamate N-methyltransferase]], where [[methylamine]] is the donor, [[L-glutamate]] is the acceptor, and [[methyltransferase]] is the EC category grouping. This same action by the transferase can be illustrated as follows:
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| :methylamine + L-glutamate <math>\rightleftharpoons</math> [[Ammonia|NH<sub>3]]</sub> + [[gamma-Glutamylmethylamide|N-methyl-L-glutamate]]<ref name="pmid5905132">{{cite journal | author = Shaw WV, Tsai L, Stadtman ER | title = The enzymatic synthesis of N-methylglutamic acid | journal = J. Biol. Chem. | volume = 241 | issue = 4 | pages = 935–45 |date=February 1966 | pmid = 5905132 | doi = }}</ref>
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| However, other accepted names are more frequently used for transferases, and are often formed as "acceptor grouptransferase" or "donor grouptransferase." For example, a [[DNA methyltransferase]] is a transferase that catalyzes the transfer of a [[methyl]] group to a [[DNA]] acceptor. In practice, many molecules are not referred to using this terminology due to more prevalent common names.<ref>{{cite web|last=Lower|first=Stephen|title=Naming Chemical Substances|url=http://www.chem1.com/acad/webtext/intro/int-5.html|work=Chem1 General Chemistry Virtual Textbook|accessdate=13 November 2013}}</ref> For example, [[RNA Polymerase]] is the modern common name for what was formerly known as RNA nucleotidyltransferase, a kind of [[nucleotidyl transferase]] that transfers [[nucleotides]] to the 3’ end of a growing [[RNA]] strand.<ref>{{cite book|last=Hausmann|first=Rudolf|title=To grasp the essence of life : a history of molecular biology|publisher=Springer|location=Dordrecht|isbn=978-90-481-6205-5|pages=198–199}}</ref> In the EC system of classification, the accepted name for RNA Polymerase is DNA-directed RNA polymerase.<ref>{{cite web|title=EC 2.7.7.6|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/7/7/6.html|work=IUBMB Enzyme Nomenclature|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=12 November 2013}}</ref>
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| ==Classification==
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| Described primarily based on the type of biochemical group transferred, transferases can be divided into ten categories (based on the [[Enzyme Commission number|EC Number]] classification).<ref name="EC2 List">{{cite web|title=EC2 Transferase Nomenclature|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=4 November 2013}}</ref> These categories comprise over 450 different unique enzymes.<ref>{{cite web|title=Transferase|url=http://www.britannica.com/EBchecked/topic/602553/transferase|work=Encyclopædia Britannica|publisher=Encyclopædia Britannica, Inc|accessdate=4 November 2013}}</ref> In the EC numbering system, transferases have been given a classification of '''EC2'''. It is important to note, that [[hydrogen]] is not considered a functional group when it comes to transferase targets; instead, hydrogen transfer is included under [[oxidoreductase]]s, due to electron transfer considerations.
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| {| class="wikitable"
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| |+ Classification of transferases into subclasses:
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| ! '''EC number''' || '''Examples''' || '''Group(s) transferred'''
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| | align=''center'' | '''[[:Category:EC 2.1|EC 2.1]]''' || [[methyltransferase]] and [[formyltransferase]] || single-[[carbon]] groups
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| |-
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| | align=''center'' | '''[[:Category:EC 2.2|EC 2.2]]''' || [[transketolase]] and [[transaldolase]] || [[aldehyde]] or [[ketone]] groups
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| | align=''center'' | '''[[:Category:EC 2.3|EC 2.3]]''' || [[acyltransferase]] || [[acyl]] groups or groups that become [[alkyl]] groups during transfer
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| | align=''center'' | '''[[:Category:EC 2.4|EC 2.4]]''' || [[glycosyltransferase]], [[hexosyltransferase]], and [[pentosyltransferase]] || [[glycosyl]] groups, as well as [[hexoses]] and [[pentoses]]
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| | align=''center'' | '''[[:Category:EC 2.5|EC 2.5]]''' || [[riboflavin synthase]] and [[chlorophyll synthase]] || [[alkyl]] or [[aryl]] groups, other than methyl groups
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| | align=''center'' | '''[[:Category:EC 2.6|EC 2.6]]''' || [[transaminase]], and [[oximinotransferase]] || [[nitrogen]]ous groups
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| | align=''center'' | '''[[:Category:EC 2.7|EC 2.7]]''' || [[phosphotransferase]], [[polymerase]], and [[kinase]] || [[phosphorus]]-containing groups; subclasses are based on the acceptor (e.g. [[alcohol]], [[carboxyl]], etc.)
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| | align=''center'' | '''[[:Category:EC 2.8|EC 2.8]]''' || [[sulfurtransferase]] and [[sulfotransferase]] || [[sulfur]]-containing groups
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| | align=''center'' | '''[[:Category:EC 2.9|EC 2.9]]''' || [[selenotransferase]] || [[selenium]]-containing groups
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| | align=''center'' | '''[[:Category:EC 2.10|EC 2.10]]''' || [[molybdenumtransferase]] and [[tungstentransferase]] || [[molybdenum]] or [[tungsten]]
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| |}
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| ==Reactions==
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| ===EC 2.1: single carbon transferases===
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| [[Image:ATCase reaction.jpg|thumb|Reaction involving aspartate transcarbamylase.]]
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| EC 2.1 includes enzymes that transfer single-carbon groups. This category consists of transfers of [[methyl]], hydroxymethyl, formyl, carboxy, carbamoyl, and amido groups.<ref>{{cite web|title=EC 2.1.3: Carboxy- and Carbamoyltransferases|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/1/3/|work=School of Biological & Chemical Sciences at Queen Mary, University of London.|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=25 November 2013}}</ref> Carbamoyltransferases, as an example, transfer a carbamoyl group from one molecule to another.<ref>{{cite web|title=carbamoyltransferase|url=http://medical-dictionary.thefreedictionary.com/carbamoyltransferase|work=The Free Dictionary|publisher=Farlex, Inc.|accessdate=25 November 2013}}</ref> Carbamoyl groups follow the formula NH<sub>2</sub>CO.<ref>{{cite web|title=carbamoyl group (CHEBI:23004)|url=http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:23004|work=ChEBI: The database and ontology of Chemical Entities of Biological Interest|publisher=European Molecular Biology Laboratory|accessdate=25 November 2013}}</ref> In [[Aspartate carbamoyltransferase|ATCase]] such a transfer is written as Carbamyl phosphate + L-aspertate <math>\rightarrow</math> L-carbamyl aspartate + [[phosphate]].<ref>{{cite journal | author = Reichard P, Hanshoff G | title = Aspartate Carbamyl Transferase from Escherichia Coli | journal = ACTA Chemica Scandinavica | year = 1956 | pages = 548–566 | url = http://actachemscand.dk/pdf/acta_vol_10_p0548-0566.pdf }}</ref>
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| ===EC 2.2: aldehyde and ketone transferases===
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| [[Image:Transaldolase reaction.svg|Reaction catalyzed by transaldolase|thumb|The reaction catalyzed by transaldolase]]
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| Enzymes that transfer aldehyde or ketone groups and included in EC 2.2. This category consists of various transketolases and transaldolases.<ref>{{cite web|title=ENZYME class 2.2.1|url=http://enzyme.expasy.org/EC/2.2.1.-|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|accessdate=25 November 2013}}</ref> Transaldolase, the namesake of aldehyde transferases, is an important part of the pentose phosphate pathway.<ref>{{cite web|title=Pentose Phosphate Pathway|url=http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/pentose.htm|work=Molecular Biochemistry II Notes|publisher=The Biochemistry and Biophysics Program at Renssalaer Polytechnic Institute|accessdate=25 November 2013}}</ref> The reaction it catalyzes consists of a transfer of a dihydroxyacetone functional group to [[Glyceraldehyde 3-phosphate]] (also known as G3P). The reaction is as follows: [[sedoheptulose 7-phosphate]] + glyceraldehyde 3-phosphate <math>\rightleftharpoons</math> [[erythrose 4-phosphate]] + [[fructose 6-phosphate]].<ref>{{cite web|title=EC 2.2.1.2 Transaldolase|url=http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/enzymes/GetPage.pl?ec_number=2.2.1.2|work=Enzyme Structures Database|publisher=European Molecular Biology Laboratory|accessdate=25 November 2013}}</ref>
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| ===EC 2.3: acyl transferases===
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| Transfer of acyl groups or acyl groups that become alkyl groups during the process of being transferred are key aspects of EC 2.3. Further, this category also differentiates between amino-acyl and non-amino-acyl groups. [[Peptidyl transferase]] is a [[ribozyme]] that facilitates formation of [[peptide bonds]] during [[translation]].<ref name="pmid19363482">{{cite journal | author = Voorhees RM, Weixlbaumer A, Loakes D, Kelley AC, Ramakrishnan V | title = Insights into substrate stabilization from snapshots of the peptidyl transferase center of the intact 70S ribosome | journal = Nat. Struct. Mol. Biol. | volume = 16 | issue = 5 | pages = 528–33 |date=May 2009 | pmid = 19363482 | pmc = 2679717 | doi = 10.1038/nsmb.1577 }}</ref> As an aminoacyltransferase, it catalyzes the transfer of a peptide to an [[aminoacyl-tRNA]], following this reaction: peptidyl-tRNA<sub>A</sub> + aminoacyl-tRNA<sub>B</sub> <math>\rightleftharpoons</math> tRNA<sub>A</sub> + peptidyl aminoacyl-tRNA<sub>B</sub>.<ref>{{cite web|title=ENZYME entry: EC 2.3.2.12|url=http://enzyme.expasy.org/EC/2.3.2.12|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|accessdate=26 November 2013}}</ref>
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| ===EC 2.4: glycosyl, hexosyl, and pentosyl transferases===
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| EC 2.4 includes enzymes that transfer [[glycosyl]] groups, as well as those that transfer hexose and pentose. [[Glycosyltransferase]] is a subcategory of EC 2.4 transferases that is involved in [[biosynthesis]] of [[disaccharides]] and [[polysaccharides]] through transfer of [[monosaccharides]] to other molecules.<ref>{{cite web|title=Keyword Glycosyltransferase|url=http://www.uniprot.org/keywords/KW-0328|work=UniProt|publisher=UniProt Consortium|accessdate=26 November 2013}}</ref> An example of a prominent glycosyltransferase is [[lactose synthase]] which is a dimer possessing two [[protein subunit]]s. Its primary action is to produce [[lactose]] from [[glucose]] and UDP-glucose.<ref name="pmid5440844">{{cite journal | author = Fitzgerald DK, Brodbeck U, Kiyosawa I, Mawal R, Colvin B, Ebner KE | title = Alpha-lactalbumin and the lactose synthetase reaction | journal = J. Biol. Chem. | volume = 245 | issue = 8 | pages = 2103–8 |date=April 1970 | pmid = 5440844 | doi = | url = http://www.jbc.org/content/245/8/2103.long }}</ref> This occurs via the following pathway: UDP-α-D-glucose + D-glucose <math>\rightleftharpoons</math> [[Uridine diphosphate|UDP]] + lactose.<ref>{{cite web|title=ENZYME entry: EC 2.4.1.22|url=http://enzyme.expasy.org/EC/2.4.1.22|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|accessdate=26 November 2013}}</ref>
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| ===EC 2.5: alkyl and aryl transferases===
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| EC 2.5 relates to enzymes that transfer alkyl or aryl groups, but does not include methyl groups. This is in contrast to functional groups that become alkyl groups when transferred, as those are included in EC 2.3. EC 2.5 currently only possesses one sub-class: Alkyl and aryl transferases.<ref>{{cite web|title=EC 2.5|url=http://www.ebi.ac.uk/intenz/query?cmd=SearchEC&ec=2.5|work=IntEnz|publisher=European Molecular Biology Laboratory|accessdate=26 November 2013}}</ref> [[Cysteine synthase]], for example, catalyzes the formation of acetic acids and [[cysteine]] from O<sub>3</sub>-acetyl-L-serine and hydrogen sulfide: O<sub>3</sub>-acetyl-L-serine + H<sub>2</sub>S <math>\rightleftharpoons</math> L-cysteine + acetate.<ref name="pmid24260346">{{cite journal | author = Qabazard B, Ahmed S, Li L, Arlt VM, Moore PK, Stürzenbaum SR | title = C. elegans Aging Is Modulated by Hydrogen Sulfide and the sulfhydrylase/cysteine Synthase cysl-2 | journal = PLoS ONE | volume = 8 | issue = 11 | pages = e80135 | year = 2013 | pmid = 24260346 | pmc = 3832670 | doi = 10.1371/journal.pone.0080135 }}</ref>
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| ===EC 2.6: nitrogenous transferases===
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| [[image:Aspartate aminotransferase reaction.png|thumb|450px|Aspartate aminotransferase can act on several different amino acids]]
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| The grouping consistent with transfer of [[nitrogenous]] groups is EC 2.6. This includes enzymes like [[transaminase]] (also known as "aminotransferase"), and a very small number of [[oximinotransferase]]s and other nitrogen group transferring enzymes. EC 2.6 previously included [[amidinotransferase]] but it has since been reclassified as a subcategory of EC 2.1 (single-carbon transferring enzymes).<ref>{{cite web|title=EC 2.6.2|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/6/2/|work=IUBMB Enzyme Nomenclatur|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=28 November 2013}}</ref> In the case of [[aspartate transaminase]], which can act on [[tyrosine]], [[phenylalanine]], and [[tryptophan]], it reversibly transfers an [[amino]] group from one molecule to the other.<ref name="pmid6143829">{{cite journal | author = Kirsch JF, Eichele G, Ford GC, Vincent MG, Jansonius JN, Gehring H, Christen P | title = Mechanism of action of aspartate aminotransferase proposed on the basis of its spatial structure | journal = J. Mol. Biol. | volume = 174 | issue = 3 | pages = 497–525 |date=April 1984 | pmid = 6143829 | doi = }}</ref>
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| The reaction, for example, follows the following order: L-aspartate +2-oxoglutarate <math>\rightleftharpoons</math> oxaloacetate + L-glutamate.<ref>{{cite web|title=ENZYME entry:2.6.1.1|url=http://enzyme.expasy.org/EC/2.6.1.1|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|accessdate=28 November 2013}}</ref>
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| ===EC 2.7: phosphorus transferases===
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| While EC 2.7 includes enzymes that transfer [[phosphorus]]-containing groups, it also includes nuclotidyl transferases as well.<ref>{{cite web|title=EC 2.7|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/7/|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=4 December 2013}}</ref> Sub-category [[phosphotransferase]] is divided up in categories based on the type of group that accepts the transfer.<ref name="EC2 Intro" /> Groups that are classified as phosphate acceptors include: alcohols, carboxy groups, nitrogenous groups, and phosphate groups.<ref name="EC2 List" /> Further constituents of this subclass of transferases are various kinases. A prominent kinase is [[cyclin-dependent kinase]] (or CDK), which comprises a sub-family of [[protein kinase]]s. As their name implies, CDKs are heavily dependent on specific [[cyclin]] molecules for [[Activation#Biochemistry|activation]].<ref name="pmid8550604">{{cite journal | author = Yee A, Wu L, Liu L, Kobayashi R, Xiong Y, Hall FL | title = Biochemical characterization of the human cyclin-dependent protein kinase activating kinase. Identification of p35 as a novel regulatory subunit | journal = J. Biol. Chem. | volume = 271 | issue = 1 | pages = 471–7 |date=January 1996 | pmid = 8550604 | doi = }}</ref> Once combined, the CDK-cyclin complex is capable of enacting its function within the cell cycle.<ref>{{cite book|last=Lewis|first=Ricki|title=Human genetics : concepts and applications|year=2008|publisher=McGraw-Hill/Higher Education|location=Boston|isbn=978-0-07-299539-8|page=32|edition=8th ed.}}</ref>
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| The reaction catalyzed by CDK is as follows: ATP + a target protein <math>\rightarrow</math> ADP + a phosphoprotein.<ref>{{cite web|title=ENZYME Entry: EC 2.7.11.22|url=http://enzyme.expasy.org/EC/2.7.11.22|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|accessdate=4 December 2013}}</ref>
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| ===EC 2.8: sulfur transferases===
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| [[File:PDB 1aqy EBI.jpg|thumb|left|Ribbon diagram of a variant structure of estrogen sulfotransferase (PDB 1aqy EBI)<ref>{{cite web|title=1aqy Summary|url=http://www.ebi.ac.uk/pdbe-srv/view/entry/1aqy/summary.html|work=Protein Data Bank in Europe Bringing Structure to Biology|publisher=The European Bioinformatics Institute|accessdate=11 December 2013}}</ref>]]
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| Transfer of sulfur-containing groups is covered by EC 2.8 and is subdivided into the subcategories of sulfurtransferases, sulfotransferases, and CoA-transferases, as well as enzymes that transfer alkylthio groups.<ref>{{cite web|title=EC 2.8 Transferring Sulfur-Containing Groups|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/0801p.html|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB).|accessdate=11 December 2013}}</ref> A specific group of sulfotransferases are those that use [[3'-Phosphoadenosine-5'-phosphosulfate|PAPS]] as a sulfate group donor.<ref>{{cite journal|last=Negishi|first=M|coauthors=Pedersen, LG; Petrotchenko, E; Shevtsov, S; Gorokhov, A; Kakuta, Y; Pedersen, LC|title=Structure and function of sulfotransferases.|journal=Archives of biochemistry and biophysics|date=Jun 15, 2001|volume=390|issue=2|pages=149–57|pmid=11396917|doi=10.1006/abbi.2001.2368}}</ref> Within this group is [[alcohol sulfotransferase]] which has a broad targeting capacity.<ref>{{cite web|title=EC 2.8 Transferring Sulfur-Containing Groups|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/0801p.html#0202|work=School of Biological & Chemical Sciences at Queen Mary, University of London.|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB).|accessdate=11 December 2013}}</ref> Due to this, alcohol sulfotransferase is also known by several other names including "hydroxysteroid sulfotransferase," "steroid sulfokinase," and "estrogen sulfotransferase."<ref>{{cite web|title=Enzyme 2.8.2.2|url=http://www.genome.jp/dbget-bin/www_bget?ec:2.8.2.2|work=Kegg: DBGET|publisher=Kyoto University Bioinformatics Center|accessdate=11 December 2013}}</ref> Decreases in its activity has been linked to human liver disease.<ref>{{cite journal|last=Ou|first=Z|coauthors=Shi, X; Gilroy, RK; Kirisci, L; Romkes, M; Lynch, C; Wang, H; Xu, M; Jiang, M; Ren, S; Gramignoli, R; Strom, SC; Huang, M; Xie, W|title=Regulation of the human hydroxysteroid sulfotransferase (SULT2A1) by RORα and RORγ and its potential relevance to human liver diseases.|journal=Molecular endocrinology (Baltimore, Md.)|date=January 2013|volume=27|issue=1|pages=106–15|pmid=23211525|doi=10.1210/me.2012-1145}}</ref> This transferase acts via the following reaction: 3'-phosphoadenylyl sulfate + an alcohol <math>\rightleftharpoons</math> adenosine 3',5'bisphosphate + an alkyl sulfate.<ref>{{cite journal|last=Sekura|first=RD|coauthors=Marcus, CJ; Lyon, ES; Jakoby, WB|title=Assay of sulfotransferases.|journal=Analytical Biochemistry|date=May 1979|volume=95|issue=1|pages=82–6|pmid=495970}}</ref>
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| ===EC 2.9: selenium transferases===
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| EC 2.9 includes enzymes that transfer [[selenium]]-containing groups.<ref>{{cite web|title=EC 2.9.1|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/9/1/|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=11 December 2013}}</ref> This category only contains two transferases, and thus is one of the smallest categories of transferase. Selenocysteine synthase, which was first added to the classification system in 1999, converts seryl-tRNA(Sec UCA) into selenocysteyl-tRNA(Sec UCA).<ref>{{cite journal|last=Forchhammer|first=K|coauthors=Böck, A|title=Selenocysteine synthase from Escherichia coli. Analysis of the reaction sequence.|journal=The Journal of Biological Chemistry|date=Apr 5, 1991|volume=266|issue=10|pages=6324–8|pmid=2007585}}</ref>
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| ===EC 2.10: metal transferases===
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| The category of EC 2.10 includes enzymes that transfer [[molybdenum]] or [[tungsten]]-containing groups. However as of 2011, only one enzyme has been added: [[molybdopterin molybdotransferase]].<ref>{{cite web|title=EC 2.10.1|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/10/1/|work=School of Biological & Chemical Sciences at Queen Mary, University of London.|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|accessdate=11 December 2013}}</ref> This enzyme is a component of MoCo biosynthesis in ''Escherichia coli''.<ref>{{cite journal|last=Nichols|first=JD|coauthors=Xiang, S; Schindelin, H; Rajagopalan, KV|title=Mutational analysis of Escherichia coli MoeA: two functional activities map to the active site cleft.|journal=Biochemistry|date=Jan 9, 2007|volume=46|issue=1|pages=78–86|pmid=17198377|doi=10.1021/bi061551q}}</ref> The reaction it catalyzes is as follows: adenylyl-molybdopterin + [[molybdate]] <math>\rightarrow</math> [[molybdenum cofactor]] + AMP.<ref>{{cite book|last=Schomburg|first=Gerhard Michal, Dietmar|title=Biochemical pathways : an atlas of biochemistry and molecular biology|year=2010|publisher=Wiley-Blackwell|location=Oxford|isbn=9780470146842|page=140|edition=2nd rev. ed.}}</ref>
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| ==Role in histo-blood group==
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| The A and B transferases are the foundation of the human [[ABO blood group]] system. Both A and B transferases are glycosyltransferases, meaning they transfer a sugar molecule onto an H-antigen.<ref name="a and b transferase 1">{{cite journal | author = Nishida C, Tomita T, Nishiyama M, Suzuki R, Hara M, Itoh Y, Ogawa H, Okumura K, Nishiyama C | title = B-transferase with a Pro234Ser substitution acquires AB-transferase activity | journal = Biosci. Biotechnol. Biochem. | volume = 75 | issue = 8 | pages = 1570–5 | year = 2011 | pmid = 21821934 | doi = }}</ref> This allows H-antigen to synthesize the [[glycoprotein]] and [[glycolipid]] conjugates that are known as the A/B [[antigens]].<ref name="a and b transferase 1" /> The full name of A transferase is alpha 1-3-N-acetylgalactosaminyltransferase<ref name="A and B transferase 3">{{cite web|title=ABO ABO blood group (transferase A, alpha 1-3-N-acetylgalactosaminyltransferase; transferase B, alpha 1-3-galactosyltransferase) [ Homo sapiens (human) ]|url=http://www.ncbi.nlm.nih.gov/gene/28|publisher=NCBI|accessdate=2 December 2013}}</ref> and its function in the cell is to add N-acetylgalactosamine to H-antigen, creating A-antigen.<ref name="A and B transferase 6">{{cite book|first=managing ed.: A. D. Smith|title=Oxford dictionary of biochemistry and molecular biology|year=2000|publisher=Oxford Univ. Press|location=Oxford [u.a.]|isbn=0198506732|page=55|edition=Rev. ed.}}</ref> The full name of B transferase is alpha 1-3-galactosyltransferase,<ref name="A and B transferase 3" /> and its function in the cell is to add a [[galactose]] molecule to H-antigen, creating B-antigen.<ref name="A and B transferase 7" />
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| It is possible for ''[[Homo sapiens]]'' to have any of four different [[blood type]]s: Type A (express A antigens), Type B (express B antigens), Type AB (express both A and B antigens) and Type O (express neither A nor B antigens).<ref>{{cite web|last=O'Neil|first=Dennis|title=ABO Blood Groups|url=http://anthro.palomar.edu/blood/ABO_system.htm|work=Human Blood: An Introduction to Its Components and Types|publisher=Behavioral Sciences Department, Palomar College|accessdate=2 December 2013}}</ref> The gene for A and B transferases is located on [[chromosome]] nine.<ref name="A and B transferases 4">{{cite web|title=ABO Blood Group (Transferase A, Alpha 1-3-N-Acetylgalactosaminyltransferase;Transferase B, Alpha 1-3-Galactosyltransferase)|url=http://www.genecards.org/cgi-bin/carddisp.pl?gene=ABO|work=GeneCards: The Human Gene Compendium|publisher=Weizmann Institute of Science|accessdate=2 December 2013}}</ref> The gene contains seven [[exon]]s and six [[intron]]s<ref name="A and B transferase 5">{{cite web|last=Moran|first=Lawrence|title=Human ABO Gene|url=http://sandwalk.blogspot.com/2007/02/human-abo-gene.html|accessdate=2 December 2013}}</ref> and the gene itself is over 18kb long.<ref name="A and B transferase 8">{{cite web|last=Kidd|first=Kenneth|title=ABO blood group (transferase A, alpha 1-3-N-acetylgalactosaminyltransferase; transferase B, alpha 1-3-galactosyltransferase)|url=http://alfred.med.yale.edu/alfred/recordinfo.asp?UNID=LO000384P|accessdate=2 December 2013}}</ref> The alleles for A and B transferases are extremely similar. The resulting enzymes only differ in 4 amino acid residues.<ref name="A and B transferase 6" /> The differing residues are located at positions 176, 235, 266, and 268 in the enzymes.<ref name="A and B transferase 7">{{cite book|first=managing ed.: A. D. Smith|title=Oxford dictionary of biochemistry and molecular biology|year=2000|publisher=Oxford Univ. Press|location=Oxford [u.a.]|isbn=0198506732|pages=82–83|edition=Rev. ed.}}</ref>
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| ==Deficiencies==
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| [[Image:Galactose-1-phosphate uridylyltransferase 1GUP.png|thumb|right|A deficiency of this transferase, [[E. coli]] galactose-1-phosphate uridyltransferase is a known cause of galactosemia]]
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| Transferase [[Deficiency (medicine)|deficiencies]] are at the root of many common [[illness]]es. The most common result of a transferase deficiency is a buildup of a [[Cellular waste product|cellular product]].
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| ===SCOT deficiency===
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| [[OXCT1|Succinyl-CoA:3-ketoacid CoA]] transferase deficiency (or [[SCOT deficiency]]) leads to a buildup of [[ketone]]s.<ref>{{cite web|title=Succinyl-CoA:3-ketoacid CoA transferase deficiency|url=http://ghr.nlm.nih.gov/condition/succinyl-coa3-ketoacid-coa-transferase-deficiency|work=Genetics Home Reference|publisher=National Institute of Health|accessdate=4 November 2013}}</ref>
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| [[Ketones]] are created upon the breakdown of fats in the body and are an important energy source.<ref name="scot deficiency 1">{{cite web|title=SUCCINYL-CoA:3-OXOACID CoA TRANSFERASE DEFICIENCY|url=http://omim.org/entry/245050|publisher=OMIM|accessdate=22 November 2013}}</ref> Inability to utilize [[ketones]] leads to intermittent [[ketoacidosis]], which usually first manifests during infancy.<ref name="scot deficiency 1" /> Disease sufferers experience nausea, vomiting, inability to feed, and breathing difficulties.<ref name="scot deficiency 1" /> In extreme cases, ketoacidosis can lead to coma and death.<ref name="scot deficiency 1" /> The deficiency is caused by [[mutation]] in the gene OXTC1.<ref name="scot deficiency 2">{{cite web|title=SCOT deficiency|url=http://rarediseases.info.nih.gov/gard/4774/scot-deficiency/resources/1|publisher=NIH|accessdate=22 November 2013}}</ref> Treatments mostly rely on controlling the diet of the patient.<ref name="scot deficiency 3">{{cite web|title=Succinyl-CoA 3-Oxoacid Transferase Deficiency|url=http://www.climb.org.uk/IMD/Sierra/Succinyl-CoA3-OxoacidTransferaseDeficiency.pdf|publisher=Climb National Information Centre|accessdate=22 November 2013}}</ref>
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| ===CPT-II deficiency===
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| [[Carnitine palmitoyltransferase II]] deficiency (also known as [[Carnitine palmitoyltransferase II deficiency|CPT-II deficiency]]) leads to an excess long chain [[fatty acids]], as the [[Human body|body]] lacks the ability to transport fatty acids into the [[mitochondria]] to be processed as a fuel source.<ref>{{cite web|title=Carnitine plamitoyltransferase I deficiency|url=http://ghr.nlm.nih.gov/condition/carnitine-palmitoyltransferase-i-deficiency|work=Genetics Home Reference|publisher=National Institute of Health|accessdate=4 November 2013}}</ref> The disease is caused by a defect in the gene CPT2.<ref name="CPT2 deficiency 1">{{cite web|last=Weiser|first=Thomas|title=Carnitine Palmitoyltransferase II Deficiency|url=http://www.ncbi.nlm.nih.gov/books/NBK1253/|publisher=NIH|accessdate=22 November 2013}}</ref> This deficiency will present in patients in one of three ways: lethal neonatal, severe infantile hepatocardiomuscular, and myopathic form.<ref name="CPT2 deficiency 1" /> The myopathic is the least severe form of the deficiency and can manifest at any point in the lifespan of the patient.<ref name="CPT2 deficiency 1" /> The other two forms appear in infancy.<ref name="CPT2 deficiency 1" /> Common symptoms of the lethal neonatal form and the severe infantile forms are liver failure, heart problems, seizures and death.<ref name="CPT2 deficiency 1" /> The myopathic form is characterized by muscle pain and weakness following vigorous exercise.<ref name="CPT2 deficiency 1" /> Treatment generally includes dietary modifications and carnitine supplements.<ref name="CPT2 deficiency 1" />
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| ===Galactosemia===
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| [[Galactosemia]] results from an inability to process galactose, a [[Monosaccharide|simple sugar]].<ref>{{cite web|title=Galactosemia|url=http://ghr.nlm.nih.gov/condition=galactosemia|work=Genetics Home Reference|publisher=National Institute of Health|accessdate=4 November 2013}}</ref> This deficiency occurs when the gene for [[galactose-1-phosphate uridylyltransferase]] (GALT) has any number of mutations, leading to a deficiency in the amount of GALT produced.<ref name="pmid12552079">{{cite journal | author = Dobrowolski SF, Banas RA, Suzow JG, Berkley M, Naylor EW | title = Analysis of common mutations in the galactose-1-phosphate uridyl transferase gene: new assays to increase the sensitivity and specificity of newborn screening for galactosemia | journal = J Mol Diagn | volume = 5 | issue = 1 | pages = 42–7 |date=February 2003 | pmid = 12552079 | pmc = 1907369 | doi = 10.1016/S1525-1578(10)60450-3 }}</ref><ref>{{cite journal|last=Murphy|first=M|coauthors=McHugh, B; Tighe, O; Mayne, P; O'Neill, C; Naughten, E; Croke, DT|title=Genetic basis of transferase-deficient galactosaemia in Ireland and the population history of the Irish Travellers.|journal=European journal of human genetics : EJHG|date=July 1999|volume=7|issue=5|pages=549–54|pmid=10439960|doi=10.1038/sj.ejhg.5200327}}</ref> There are two forms of Galactosemia: classic and Duarte.<ref>{{cite journal|last=Mahmood|first=U|coauthors=Imran, M; Naik, SI; Cheema, HA; Saeed, A; Arshad, M; Mahmood, S|title=Detection of common mutations in the GALT gene through ARMS.|journal=Gene|date=Nov 10, 2012|volume=509|issue=2|pages=291–4|pmid=22963887|doi=10.1016/j.gene.2012.08.010}}</ref> Duarte galactosemia is generally less severe than classic galactosemia and is caused by a deficiency of [[galactokinase]].<ref name="Galactosemia 1">{{cite web|title=Galactosemia|url=http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/373/viewFullReport|publisher=NORD|accessdate=22 November 2013}}</ref> Galactosemia renders infants unable to process the sugars in breast milk, which leads to vomiting and [[Anorexia (symptom)|anorexia]] within days of birth.<ref name="Galactosemia 1" /> Most symptoms of the disease are caused by a buildup of [[galactose-1-phosphate]] in the body.<ref name="Galactosemia 1" /> Common symptoms include liver failure, [[sepsis]], failure to grow, and mental impairment, among others.<ref>{{cite journal|last=Elsas|first=LJ|coauthors=Pagon, RA; Adam, MP; Bird, TD; Dolan, CR; Fong, CT; Stephens, K|title=Galactosemia|year=1993|pmid=20301691}}</ref> Buildup of a second toxic substance, [[galactitol]], occurs in the lenses of the eyes, causing [[cataracts]].<ref>{{cite journal|last=Bosch|first=AM|title=Classical galactosaemia revisited.|journal=Journal of Inherited Metabolic Disease|date=August 2006|volume=29|issue=4|pages=516–25|pmid=16838075|doi=10.1007/s10545-006-0382-0}}</ref> Currently, the only available treatment is early diagnosis followed by adherence to a diet devoid of lactose, and prescription of antibiotics for infections that may develop.<ref>{{cite journal|last=Karadag|first=N|coauthors=Zenciroglu, A; Eminoglu, FT; Dilli, D; Karagol, BS; Kundak, A; Dursun, A; Hakan, N; Okumus, N|title=Literature review and outcome of classic galactosemia diagnosed in the neonatal period.|journal=Clinical laboratory|year=2013|volume=59|issue=9-10|pages=1139–46|pmid=24273939}}</ref>
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| ===Choline acetyltransferase deficiencies===
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| [[Choline acetyltransferase]] (also known as ChAT or CAT) is an important enzyme which produces the [[neurotransmitter]] [[acetylcholine]].<ref name="Acetyltransferase Gen Info">{{cite journal|last=Strauss|first=WL|coauthors=Kemper, RR; Jayakar, P; Kong, CF; Hersh, LB; Hilt, DC; Rabin, M|title=Human choline acetyltransferase gene maps to region 10q11-q22.2 by in situ hybridization.|journal=Genomics|date=February 1991|volume=9|issue=2|pages=396–8|pmid=1840566|doi=10.1016/0888-7543(91)90273-H}}</ref> Acetylcholine is involved in many neuropsychic functions such as memory, attention, sleep and arousal.<ref>{{cite journal|last=Braida|first=D|coauthors=Ponzoni, L; Martucci, R; Sparatore, F; Gotti, C; Sala, M|title=Role of neuronal nicotinic acetylcholine receptors (nAChRs) on learning and memory in zebrafish.|journal=Psychopharmacology|date=Dec 6, 2013|pmid=24311357|doi=10.1007/s00213-013-3340-1}}</ref><ref>{{cite journal|last=Stone|first=TW|title=Cholinergic mechanisms in the rat somatosensory cerebral cortex.|journal=The Journal of physiology|date=September 1972|volume=225|issue=2|pages=485–99|pmid=5074408|pmc=1331117}}</ref><ref>{{cite journal|last=Guzman|first=MS|coauthors=De Jaeger, X; Drangova, M; Prado, MA; Gros, R; Prado, VF|title=Mice with selective elimination of striatal acetylcholine release are lean, show altered energy homeostasis and changed sleep/wake cycle.|journal=Journal of Neurochemistry|date=March 2013|volume=124|issue=5|pages=658–69|pmid=23240572|doi=10.1111/jnc.12128}}</ref>
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| The enzyme is globular in shape and consists of a single amino acid chain.<ref name="choline acetyltransferase 1 and 4" /> ChAT functions to transfer an [[acetyl group]] from acetyl co-enzyme A to [[choline]] in the [[synapse]]s of [[nerve]] cells and exists in two forms: soluble and membrane bound.<ref name="choline acetyltransferase 1 and 4">{{cite journal | author = Oda Y | title = Choline acetyltransferase: the structure, distribution and pathologic changes in the central nervous system | journal = Pathol. Int. | volume = 49 | issue = 11 | pages = 921–37 |date=November 1999 | pmid = 10594838 | doi = 10.1046/j.1440-1827.1999.00977.x| url = http://onesci.com/journals/science_journal_97.pdf }}</ref> The ChAT gene is located on [[chromosome]] 10.<ref name="Chat Code">{{cite web|title=Choline O-Acetyltransferase|url=http://www.genecards.org/cgi-bin/carddisp.pl?gene=CHAT|work=GeneCards: The Human Gene Compendium|publisher=Weizmann Institute of Science|accessdate=5 December 2013}}</ref>
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| ====Alzheimer's disease====
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| Decreased expression of ChAT is one of the hallmarks of [[Alzheimer’s disease]].<ref>{{cite journal|last=Szigeti|first=C|coauthors=Bencsik, N; Simonka, AJ; Legradi, A; Kasa, P; Gulya, K|title=Long-term effects of selective immunolesions of cholinergic neurons of the nucleus basalis magnocellularis on the ascending cholinergic pathways in the rat: a model for Alzheimer's disease.|journal=Brain Research Bulletin|date=May 2013|volume=94|pages=9–16|pmid=23357177|doi=10.1016/j.brainresbull.2013.01.007}}</ref> Patients with Alzheimer’s disease show a 30 to 90% reduction in activity in several regions of the brain, including the [[temporal lobe]], the [[parietal lobe]] and the [[frontal lobe]].<ref name="Choline acetyltransferase 3">{{cite journal | author = González-Castañeda RE, Sánchez-González VJ, Flores-Soto M, Vázquez-Camacho G, Macías-Islas MA, Ortiz GG | title = Neural restrictive silencer factor and choline acetyltransferase expression in cerebral tissue of Alzheimer's Disease patients: A pilot study | journal = Genet. Mol. Biol. | volume = 36 | issue = 1 | pages = 28–36 |date=March 2013 | pmid = 23569405 | pmc = 3615522 | doi = 10.1590/S1415-47572013000100005 }}</ref> However, ChAT deficiency is not believed to be the main cause of this disease.<ref name="choline acetyltransferase 1 and 4" />
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| ====Amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)====
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| Patients with [[Amyotrophic lateral sclerosis|ALS]] show a marked decrease in ChAT activity in motor neurons in the [[spinal cord]] and [[brain]].<ref name="Choline acetyltransferase 5">{{cite journal | author = Rowland LP, Shneider NA | title = Amyotrophic lateral sclerosis | journal = N. Engl. J. Med. | volume = 344 | issue = 22 | pages = 1688–700 |date=May 2001 | pmid = 11386269 | doi = 10.1056/NEJM200105313442207 }}</ref> Low levels of ChAT activity are an early indication of the disease and are detectable long before motor neurons begin to die. This can even be detected before the patient is [[symptomatic]].<ref name="choline acetyltransferase 6">{{cite journal | author = Casas C, Herrando-Grabulosa M, Manzano R, Mancuso R, Osta R, Navarro X | title = Early presymptomatic cholinergic dysfunction in a murine model of amyotrophic lateral sclerosis | journal = Brain Behav | volume = 3 | issue = 2 | pages = 145–58 |date=March 2013 | pmid = 23531559 | pmc = 3607155 | doi = 10.1002/brb3.104 }}</ref>
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| ====Huntington’s disease====
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| Patients with [[Huntington’s disease|Huntington’s]] also show a marked decrease in ChAT production.<ref>{{cite journal|last=Smith|first=R|coauthors=Chung, H; Rundquist, S; Maat-Schieman, ML; Colgan, L; Englund, E; Liu, YJ; Roos, RA; Faull, RL; Brundin, P; Li, JY|title=Cholinergic neuronal defect without cell loss in Huntington's disease.|journal=Human Molecular Genetics|date=Nov 1, 2006|volume=15|issue=21|pages=3119–31|pmid=16987871|doi=10.1093/hmg/ddl252}}</ref> Though the specific cause of the reduced production is not clear, it is believed that the death of medium sized motor neurons with spiny [[dendrite]]s leads to the lower levels of ChAT production.<ref name="choline acetyltransferase 1 and 4" />
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| ====Schizophrenia====
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| Patients with Schizophrenia also exhibit decreased levels of ChAT, localized to the [[Mesopontine|mesopontine tegment]] of the brain<ref>{{cite journal|last=Karson|first=CN|coauthors=Casanova, MF; Kleinman, JE; Griffin, WS|title=Choline acetyltransferase in schizophrenia.|journal=The American Journal of Psychiatry|date=March 1993|volume=150|issue=3|pages=454–9|pmid=8434662}}</ref> and the [[nucleus accumbens]],<ref name="choline acetyltransferase 7">{{cite journal | author = Mancama D, Mata I, Kerwin RW, Arranz MJ | title = Choline acetyltransferase variants and their influence in schizophrenia and olanzapine response | journal = Am. J. Med. Genet. B Neuropsychiatr. Genet. | volume = 144B | issue = 7 | pages = 849–53 |date=October 2007 | pmid = 17503482 | doi = 10.1002/ajmg.b.30468 | url = }}</ref> which is believed to correlate with the decreased cognitive functioning experienced by these patients.<ref name="choline acetyltransferase 1 and 4" />
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| ====Sudden infant death syndrome(SIDS)====
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| Recent studies have shown that [[Sudden infant death syndrome|SIDS]] infants show decreased levels of ChAT in both the [[hypothalamus]] and the [[striatum]].
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| <ref name="choline acetyltransferase 1 and 4" /> SIDS infants also display fewer neurons capable of producing ChAT in the vagus system.<ref name="choline acetyltransferase 8">{{cite journal | author = Mallard C, Tolcos M, Leditschke J, Campbell P, Rees S | title = Reduction in choline acetyltransferase immunoreactivity but not muscarinic-m2 receptor immunoreactivity in the brainstem of SIDS infants | journal = J. Neuropathol. Exp. Neurol. | volume = 58 | issue = 3 | pages = 255–64 |date=March 1999 | pmid = 10197817 | doi = 10.1097/00005072-199903000-00005 }}</ref> These defects in the medulla could lead to an inability to control essential [[Autonomic function|autonomic]] functions such as the [[cardiovascular]] and [[respiratory]] systems.<ref name="choline acetyltransferase 8"/>
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| ====Congenital myasthenic syndrome (CMS)====
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| [[Congenital myasthenic syndrome|CMS]] is a family of diseases that are characterized by defects in [[neuromuscular transmission]] which leads to recurrent bouts of [[apnea]] (inability to breathe) that can be fatal.<ref>{{cite journal|last=Engel|first=AG|coauthors=Shen, XM; Selcen, D; Sine, S|title=New horizons for congenital myasthenic syndromes.|journal=Annals of the New York Academy of Sciences|date=December 2012|volume=1275|pages=54–62|pmid=23278578|url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3546605/|pmc=3546605|doi=10.1111/j.1749-6632.2012.06803.x}}</ref> ChAT deficiency is implicated in myasthenia syndromes where the transition problem occurs [[presynaptic]]ally.<ref name="choline acetyltransferase 9">{{cite journal | author = Maselli RA, Chen D, Mo D, Bowe C, Fenton G, Wollmann RL | title = Choline acetyltransferase mutations in myasthenic syndrome due to deficient acetylcholine resynthesis | journal = Muscle Nerve | volume = 27 | issue = 2 | pages = 180–7 |date=February 2003 | pmid = 12548525 | doi = 10.1002/mus.10300 }}</ref> These syndromes are characterized by the patients’ inability to resynthesize [[acetylcholine]].<ref name="choline acetyltransferase 9" />
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| ==Uses in biotechnology==
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| ===Terminal transferases===
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| [[Terminal deoxynucleotidyl transferase|Terminal transferases]] are transferases that can be used to label DNA or to produce [[plasmid vector]]s.<ref name=TerminalTransferase>{{cite web|last=Bowen|first=R|title=Terminal Transferase|url=http://www.vivo.colostate.edu/hbooks/genetics/biotech/enzymes/tt.html|work=Biotechnology and Genetic Engineering|publisher=Colorado State University|accessdate=10 November 2013}}</ref> It accomplishes both of these tasks by adding [[deoxynucleotides]] in the form of a template to the [[Directionality (molecular biology)|downstream]] end or [[Sticky and blunt ends|3']] end of an existing DNA molecule.
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| Terminal transferase is one of the few DNA polymerases that can function without an RNA primer.<ref name="TerminalTransferase" />
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| ===Glutathione transferases===
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| The family of glutathione transferases (GST) is extremely diverse, and therefore can be used for a number of biotechnological purposes. Plants use glutathione transferases as a means to segregate toxic metals from the rest of the cell.<ref name="plant glutathiones 1">{{cite book|last=Kumar|first=Ashwani, Sudhir K. Sopory|title=Recent advances in plant biotechnology and its applications : Prof. Dr. Karl-Hermann Neumann commemorative volume|year=2008|publisher=I.K. International Pub. House|location=New Delhi|isbn=9788189866099}}</ref> These glutathione transferases can be used to create [[biosensors]] to detect contaminants such as herbicides and insecticides.<ref name="plant glutathiones 2">{{cite journal | author = Chronopoulou EG, Labrou NE | title = Glutathione transferases: emerging multidisciplinary tools in red and green biotechnology | journal = Recent Pat Biotechnol | volume = 3 | issue = 3 | pages = 211–23 | year = 2009 | pmid = 19747150 | doi = }}</ref> Glutathione transferases are also used in transgenic plants to increase resistance to both biotic and abiotic stress.<ref name="plant glutathiones 2" /> [[Glutathione S-transferase|Glutathione transferases]] are currently being explored as targets for [[Chemotherapy|anti-cancer medications]] due to their role in [[drug resistance]].<ref name="plant glutathiones 2" /> Further, glutathione transferase genes have been investigated due to their ability to prevent [[Oxidative stress|oxidative damage]] and have shown improved resistance in [[Transgenesis|transgenic]] [[cultigen]]s.<ref name="pmid22174645">{{cite journal | author = Sytykiewicz H | title = Expression Patterns of Glutathione Transferase Gene (GstI) in Maize Seedlings Under Juglone-Induced Oxidative Stress | journal = Int J Mol Sci | volume = 12 | issue = 11 | pages = 7982–95 | year = 2011 | pmid = 22174645 | pmc = 3233451 | doi = 10.3390/ijms12117982 }}</ref>
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| ===Rubber transferases===
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| Currently the only available commercial source of natural [[rubber]] is the [[Hevea brasiliensis|Hevea]] plant (Hevea brasiliensis). Natural rubber is superior to synthetic rubber in a number of commercial uses.<ref name="What is Rubber?">{{cite web|last=Shintani|first=David|title=What is Rubber?|url=http://www.ag.unr.edu/shintani/Elastomics/rubber%20introduction.htm|work=Elastomics|publisher=University of Nevada, Reno|accessdate=23 November 2013}}</ref> Efforts are being made to produce transgenic plants capable of synthesizing natural rubber, including [[tobacco]] and [[sunflower]].<ref name="Rubber 1">{{cite web|title=DEVELOPMENT OF DOMESTIC NATURAL RUBBER-PRODUCING INDUSTRIAL CROPS THROUGH BIOTECHNOLOGY|url=http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408518|publisher=USDA|accessdate=23 November 2013}}</ref> These efforts are focused on sequencing the subunits of the rubber transferase enzyme complex in order to transfect these genes into other plants.<ref name="Rubber 1" />
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| ==See also==
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| * [http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/intro.html EC 2 Introduction] from the Department of Chemistry at [[Queen Mary, University of London]]
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| ==References==
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| {{reflist|colwidth=30em}}
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| {{Enzymes}}
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| {{Transferases}}
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| [[Category:Transferases| ]]
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