Acetolactate decarboxylase explained

acetolactate decarboxylase
Ec Number:	4.1.1.5
Cas Number:	9025-02-9
Go Code:	0047605

The enzyme acetolactate decarboxylase catalyzes the chemical reaction

(S)-2-hydroxy-2-methyl-3-oxobutanoate

\rightleftharpoons (R)-2-acetoin + CO₂

Hence, this enzyme has one substrate, (S)-2-hydroxy-2-methyl-3-oxobutanoate, and two products, (R)-2-acetoin and CO₂.^[1]

This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is (S)-2-hydroxy-2-methyl-3-oxobutanoate carboxy-lyase [(R)-2-acetoin-forming]. Other names in common use include alpha-acetolactate decarboxylase, and (S)-2-hydroxy-2-methyl-3-oxobutanoate carboxy-lyase. This enzyme participates in butanoate metabolism and c5-branched dibasic acid metabolism.

Structural studies

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .

References

• Stormer FC . 1967 . Isolation of crystalline pH 6 acetolactate-forming enzyme from Aerobacter aerogenes . J. Biol. Chem. . 242 . 1756 - 9 . 6024768 . 8 .

Notes and References

1. Hill RK, Sawada S, Arfin SM . 1979 . Stereochemistry of valine and isoleucine biosynthesis. IV Synthesis, configuration, and enzymatic specificity of alpha-acetolactate and alpha-aceto-alpha-hydroxybutyrate . Bioorg. Chem. . 8 . 175 - 189 . 10.1016/0045-2068(79)90003-8 . 2 .