View source for Cholestenol Delta-isomerase

{{enzyme
| Name = D-lysine 5,6-aminomutase
| EC_number = 5.4.3.4
| CAS_number = 9075-70-1
| IUBMB_EC_number = 5/4/3/4
| GO_code = 0047826
| image = 
| width = 
| caption = 
}}
{{Infobox protein family
| Symbol = Lys-AminoMut_A
| Name = D-Lysine 5,6-aminomutase alpha subunit
| image = PDB 1xrs EBI.jpg
| width = 
| caption = crystal structure of lysine 5,6-aminomutase in complex with plp, cobalamin, and 5'-deoxyadenosine
| Pfam = PF09043
| Pfam_clan =  
| InterPro = IPR015130
| SMART = 
| PROSITE = 
| MEROPS = 
| SCOP = 
| TCDB = 
| OPM family = 
| OPM protein = 
| CAZy = 
| CDD = 
}}
In [[enzymology]], a '''D-lysine 5,6-aminomutase''' ({{EC number|5.4.3.4}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:D-lysine <math>\rightleftharpoons</math> 2,5-diaminohexanoate

Hence, this enzyme has one [[substrate (biochemistry)|substrate]], [[D-lysine]], and one [[product (chemistry)|product]], [[2,5-diaminohexanoate]].

This enzyme belongs to the family of [[isomerase]]s, specifically those intramolecular [[transferase]]s transferring amino groups.  The systematic name of this enzyme class is '''D-2,6-diaminohexanoate 5,6-aminomutase'''. Other names in common use include '''D-alpha-lysine mutase''', and '''adenosylcobalamin-dependent D-lysine 5,6-aminomutase'''.  This enzyme participates in [[lysine degradation]].  It employs one [[cofactor (biochemistry)|cofactor]], [[cobamide]].  

==Structure==
The [[secondary structure|structure]] of the alpha subunit is predominantly a PLP-binding [[TIM barrel]] domain, with several additional [[alpha helix|alpha-helices]] and beta-strands at the [[N-terminus|N]] and [[C-terminus|C termini]]. These [[Alpha helix|helices]] and strands form an intertwined accessory clamp structure that wraps around the sides of the TIM barrel and extends up toward the Ado [[ligand (biochemistry)|ligand]] of the Cbl [[cofactor (biochemistry)|cofactor]], providing most of the interactions observed between the protein and the Ado ligand of the Cbl, suggesting that its role is mainly in stabilising AdoCbl in the precatalytic resting state.<ref name="pmid15514022">{{cite journal| author=Berkovitch F, Behshad E, Tang KH, Enns EA, Frey PA, Drennan CL| title=A locking mechanism preventing radical damage in the absence of substrate, as revealed by the x-ray structure of lysine 5,6-aminomutase. | journal=Proc Natl Acad Sci U S A | year= 2004 | volume= 101 | issue= 45 | pages= 15870–5 | pmid=15514022 | doi=10.1073/pnas.0407074101 | pmc=528771   }} </ref>

==References==
{{reflist|1}}

==Further reading==
* {{cite journal | author = Morley CG, Stadtman TC | year = 1970 | title = Studies on the fermentation of D-alpha-lysine. Purification and properties of an adenosine triphosphate regulated B 12-coenzyme-dependent D-alpha-lysine mutase complex from Clostridium sticklandii | journal = Biochemistry.  | volume = 9 | pages = 4890&ndash;900  | pmid = 5480154 | doi = 10.1021/bi00827a010 | issue = 25 }}
* {{cite journal | author = Stadtman TC, Tsai L | year = 1967 | title = A cobamide coenzyme dependent migration of the epsilon-amino group of D-lysine | journal = Biochem. Biophys. Res. Commun.  | volume = 28 | pages = 920&ndash;6  | pmid = 4229021 | doi = 10.1016/0006-291X(67)90067-8 | issue = 6 }}

{{isomerase-stub}}

{{InterPro content|IPR015130}}

[[Category:Protein domains]]
[[Category:EC 5.4.3]]
[[Category:Cobamide enzymes]]
[[Category:Enzymes of unknown structure]]