Disease relevance of ECs4704

• The amino acid sequence of Salmonella transaminase B is 97.4% identical with that of Escherichia coli, differing in only eight amino acid positions [1].

High impact information on ECs4704

• Amino acid sequence alignment of BCATc with D-AAT suggests that the folding pattern of the overlapping mammalian BCATc sequence is similar to that of D-AAT and indicates that orientation of the pyridoxal phosphate cofactor in the active site of the eukaryotic BCAT is the same as in D-AAT [2].
• Thus, BCAT are the only eukaryotic aminotransferases to abstract and replace the proton on the re face of the pyridoxal phosphate cofactor [2].
• Valine treatment of nonstarved or methionine-starved cells led to the expected increase in threonine deaminase and transaminase B activities [3].
• Sequence comparisons of transaminase B to other known aminotransferase sequences revealed limited sequence similarity (24-33%) when conserved amino acid substitutions are allowed and alignments were forced to occur on the coenzyme-binding site [1].
• This inhibition, along with the inhibition of transaminase B, accounted for the isoleucine-plus-valine requirement of E. coli in the presence of beta-chloro-L-alanine [4].

Chemical compound and disease context of ECs4704

• Transaminase B from Escherichia coli: quaternary structure, amino-terminal sequence, substrate specificity, and absence of a separate valine-alpha-ketoglutarate activity [5].
• Escherichia coli can synthesize alpha-ketoisovalerate, the precursor of valine, leucine, and pantothenate, by three routes: anabolically via dihydroxyacid dehydrase and catabolically via both the branched-chain amino acid transaminase (transaminase B) and the alanine-valine transaminase (transaminase C) [6].

Biological context of ECs4704

• Cysteine, mercaptoethylamine, and homocysteine were inhibitors of threonine deaminase but not transaminase B, two enzymes of the ilvEDA operon [7].

Associations of ECs4704 with chemical compounds

• In the two latter cases, Apm was associated with antibacterial amino acid beta-chloro-L-alanine [L-Ala(Cl)], an inhibitor of alanine racemase and transaminase B [8].
• The concentration of accumulated L-isoleucine increased by twofold after the additional introduction of the genes for dihyroxyacid dehydratase (DH) and transaminase-B (TA-B), and the intermediates no longer accumulated [9].

References