The 1.9 A structure of the branched-chain amino-acid transaminase (IlvE) from Mycobacterium tuberculosis.

ABSTRACT: Unlike mammals, bacteria encode enzymes that synthesize branched-chain amino acids. The pyridoxal 50-phosphate-dependent transaminase performs the final biosynthetic step in these pathways, converting keto acid precursors into -amino acids. The branched-chain amino-acid transaminase from Mycobacterium tuberculosis (MtIlvE) has been crystallized and its structure has been solved at 1.9 angstrom resolution. The MtIlvE monomer is composed of two domains that interact to form the active site. The biologically active form of IlvE is a homodimer in which each monomer contributes a substrate-specificity loop to the partner molecule. Additional substrate selectivity may be imparted by a conserved N-terminal Phe30 residue, which has previously been observed to shield the active site in the type IV

SUBMITTER: Tremblay LW 

PROVIDER: S-EPMC2777029 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature