HMM Summary Page: TIGR00118

Functionacetolactate synthase, large subunit, biosynthetic type
Gene SymbolilvB
Trusted Cutoff538.35
Domain Trusted Cutoff538.35
Noise Cutoff489.00
Domain Noise Cutoff489.00
Isology Typeequivalog
EC Number2.2.1.6
HMM Length557
Mainrole CategoryAmino acid biosynthesis
Subrole CategoryPyruvate family
Gene Ontology TermGO:0003984: acetolactate synthase activity molecular_function
GO:0005948: acetolactate synthase complex cellular_component
GO:0009097: isoleucine biosynthetic process biological_process
GO:0009099: valine biosynthetic process biological_process
AuthorHaft DH
Entry DateApr 20 1999 2:06PM
Last ModifiedFeb 14 2011 3:27PM
CommentTwo groups of proteins form acetolactate from two molecules of pyruvate. The type of acetolactate synthase described in this model also catalyzes the formation of acetohydroxybutyrate from pyruvate and 2-oxobutyrate, an early step in the branched chain amino acid biosynthesis; it is therefore also termed acetohydroxyacid synthase. In bacteria, this catalytic chain is associated with a smaller regulatory chain in an alpha2/beta2 heterotetramer. Acetolactate synthase is a thiamine pyrophosphate enzyme. In this type, FAD and Mg++ are also found. Several isozymes of this enzyme are found in E. coli K12, one of which contains a frameshift in the large subunit gene and is not expressed.
ReferencesA2 hmmalign DR PROSITE; PDOC00166; DR PFAM; PF00205; TPP_enzymes; RN [1] RM 97254452 RT Cloning and phylogenetic analysis of the genes encoding acetohydroxyacid synthase from the archaeon Methanococcus aeolicus. RN [2] RM 98322107 RT Biosynthesis of 2-aceto-2-hydroxy acids: acetolactate synthases and acetohydroxyacid synthases. RA Chipman D, Barak Z, Schloss JV; RL Biochim Biophys Acta 1998 Jun 29;1385(2):401-19 SE TIGR GA hmmls AL clustalw, belvu DR OUTGROUP; SP:P30146; glyoxylate carboligase; E. coli
Genome PropertyGenProp0162: isoleucine biosynthesis from threonine and pyruvate (HMM)
GenProp0163: valine biosynthesis from pyruvate (HMM)
GenProp0164: leucine biosynthesis from pyruvate and acetyl-CoA (HMM)