2.2.1.6	evolution	acetolactate synthase and pyruvate decarboxylase are both thiamine diphosphate-dependent enzymes that use pyruvate as a substrate, but they produce different products.Whereas pyruvate decarboxylase catalyzes the non-oxidative decarboxylation of pyruvate to acetaldehyde, acetolactate synthase, which is involved in the biosynthesis of branched amino acids (Val, Leu, Ile), catalyzes the carboligation between two pyruvate molecules to form an acetolactate molecule and carbon dioxide, structural and functional similarities of the enzymes, overview	-, 735039	
2.2.1.6	evolution	the enzyme belongs to the ALS enzyme family that forms a distinct subgroup of ThDP-dependent enzymes. The ALS subfamily differs significantly in structure and possibly in catalytic mechanism, phylogenetic analysis. The ThDP-dependent enzymes cluster into three distinct sequence groups: acetolactate synthases, acetohydroxyacid synthases, and carboxylases. Eventhough ALS and AHAS catalyze the same reaction, they show different cofactors and domain structure: AHAS family enzymes have both catalytic and regulatory subunits, structure comparisons, overview	-, 733658	
2.2.1.6	evolution	three types of isozymes, AHAS I, II, III, are found in Enterobacteria encoded by ilvBN, ilvGMEDA, ilvIH operons, respectively. Bacterial AHAS consists of a regulatory and a catalytic subunit	-, 733685	
2.2.1.6	evolution	two types of ALSs, anabolic acetohydroxyacid synthase (AHAS) and catabolic ALSs (cALS). The anabolic AHAS is primarily found in plants, fungi, and bacteria, is involved in the biosynthesis of branched-chain amino acids, and contains FAD, whereas the cALS is found only in some bacteria and is involved in the butanediol fermentation pathway. Both of the enzymes are thiamine diphosphate-dependent and require a divalent metal ion for catalytic activity. The catabolic ALS can be distinguished from anabolic AHAS by a low optimal pH of about pH 6.0, FAD-independent functionality, a genetic location within the butanediol operon, and lack of a regulatory subunit. In all of the crystal structures of ThDP-dependent enzymes determined to date, with the exception of glyoxylate carbo-ligase (GCL), a highly conerved glutamate residue is found at hydrogen-bonding distance from the N1' atom of the aminopyrimidine ring of the boundThDP and plays a key role in catalysis. In Enterococcus faecalis it is Glu49	733597	
2.2.1.6	malfunction	deletion of the als gene abolishes acetoin production. Deletion of gene als in an engineered strain of Pyrococcus furiosus containing an additional pathway for ethanol production significantly improves the yield of ethanol	734625	
2.2.1.6	malfunction	deletion of the enzyme gene abolishes acetoin production	734625	
2.2.1.6	malfunction	enzyme inhibition abolishes biosynthesis of brachend chain amino acids and leads to bacteriostasis	-, 733685	
2.2.1.6	malfunction	the A205F substitution in acetolactate synthase, confirmed in a population of allotetraploid annual bluegrass, confers resistance to imidazolinone, sulfonylurea, triazolopyrimidines, sulfonylaminocarbonyl triazolinones, and pyrimidinyl(thio)benzoate herbicides	734994	
2.2.1.6	malfunction	the als defective strain, which is incapable of producing C4 compounds, appears sensitive to pyruvate under acidic conditions rendering it unable to grow. Accordingly, the als-mutant strain shows a simultaneous inability to alkalinize internal and external media	-, 733995	
2.2.1.6	malfunction	the conserved His84 and Gln86 residues lie in the catalytic dimer interface of the enzyme. Mutational analyses of these invariants lead to significant reduction in their activity with reduced affinity toward the substrate	-, 733747