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{{enzyme
| Name = 4-hydroxy-2-oxovalerate aldolase
| EC_number = 4.1.3.39
| CAS_number = 
| IUBMB_EC_number = 4/1/3/39
| GO_code = 
| image = 
| width = 
| caption = 
}}

In [[enzymology]], a '''4-hydroxy-2-oxovalerate aldolase''' ({{EC number|4.1.3.39}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:4-hydroxy-2-oxopentanoate <math>\rightleftharpoons</math> acetaldehyde + pyruvate

Hence, this enzyme has one [[substrate (biochemistry)|substrate]], [[4-hydroxy-2-oxopentanoate]], and two [[product (chemistry)|products]], [[acetaldehyde]] and [[pyruvate]]. Baker ''et al.''. showed that BphI, a member of this family from Burkholderia xenovorans LB400 was able to utilize 4-hydroxy- 2-oxohexanoate (HOHA) with equal catalytic efficiency as 4-hydroxy-2-oxopentanoate, producing propionaldehyde + pyruvate. Furthermore, the enzyme was also able to  catalyze the cleavage of 4-hydroxy-2-oxoheptanoate (HOHEP), forming butryaldehyde + pyruvate. Baker ''et al.''. we also able to show that acetaldehyde and propionaldehyde are not released into the bulk solvent, but are channeled to an associated acetaldehyde dehydrogenase known as BphJ. This is the first demonstration of substrate channeling in this family of enzymes.

This enzyme belongs to the family of [[lyase]]s, specifically the oxo-acid-lyases, which cleave carbon-carbon bonds.  The systematic name of this enzyme class is '''4-hydroxy-2-oxopentanoate pyruvate-lyase (acetaldehyde-forming)'''. Other names in common use include '''4-hydroxy-2-ketovalerate aldolase''', '''HOA''', '''DmpG''', '''BphI''', '''4-hydroxy-2-oxovalerate pyruvate-lyase''', and '''4-hydroxy-2-oxopentanoate pyruvate-lyase'''.  This enzyme participates in 8 [[metabolism|metabolic pathways]]: [[phenylalanine metabolism]], [[benzoate degradation via hydroxylation]], [[biphenyl degradation]], [[toluene and xylene degradation]], [[1,4-dichlorobenzene degradation]], [[fluorene degradation]], [[carbazole degradation]], and [[styrene degradation]].

==References==
{{reflist|1}}
* {{cite journal | author = Manjasetty BA, Powlowski J, Vrielink A | year = 2003 | title = Crystal structure of a bifunctional aldolase-dehydrogenase: sequestering a reactive and volatile intermediate | journal = [[Proc. Natl. Acad. Sci. USA]]  | volume = 100 | pages = 6992&ndash;7  | pmid = 12764229 | doi = 10.1073/pnas.1236794100 | issue = 12 | pmc = 165818 }}
* {{cite journal | author = Powlowski J, Sahlman L, Shingler V | year = 1993 | title = Purification and properties of the physically associated meta-cleavage pathway enzymes 4-hydroxy-2-ketovalerate aldolase and aldehyde dehydrogenase (acylating) from Pseudomonas sp. strain CF600 | journal = [[J. Bacteriol.]]  | volume = 175 | pages = 377&ndash;85  | pmid = 8419288 | issue = 2 | pmc = 196151 }}
* {{cite journal | author = Manjasetty BA, Croteau N, Powlowski J, Vrielink A | year = 2001 | title = Crystallization and preliminary X-ray analysis of dmpFG-encoded 4-hydroxy-2-ketovalerate aldolase--aldehyde dehydrogenase (acylating) from Pseudomonas sp. strain CF600 | journal = [[Acta Crystallogr. D]] | volume = 57 | pages = 582&ndash;5  | pmid = 11264589 | doi = 10.1107/S0907444901000439 | issue = Pt 4 }}
* Baker, P., Pan, D., Carere, J., Rossi, A., Wang, W., and Seah, S. Y. (2009) "Characterization of an Aldolase-Dehydrogenase Complex That Exhibits Substrate Channeling in the Polychlorinated Biphenyls Degradation Pathway", Biochemistry. {{doi|10.1021/bi9006644}}. PMID 19476337

{{DEFAULTSORT:4-Hydroxy-2-Oxovalerate Aldolase}}
[[Category:EC 4.1.3]]
[[Category:Enzymes of unknown structure]]


{{4.1-enzyme-stub}}