1chd | pdb_00001chd
CHEB METHYLESTERASE DOMAIN
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Overview
Signaling activity of bacterial chemotaxis transmembrane receptors is, modulated by reversible covalent modification of specific receptor, glutamate residues. The level of receptor methylation results from the, activities of a specific S-adenosylmethionine-dependent methyltransferase, CheR, and the CheB methylesterase, which catalyzes hydrolysis of receptor, glutamine or methylglutamate side-chains to glutamic acid. The CheB, methylesterase belongs to a large family of response regulator proteins in, which N-terminal regulatory domains control the activities of C-terminal, effector domains. The crystal structure of the catalytic domain of the, Salmonella typhimurium CheB methylesterase has been determined at 1.75 A, resolution. The domain has a modified, doubly wound alpha/beta fold in, which one of the helices is replaced by an anti-parallel beta-hairpin., Previous biochemical and mutagenesis data, suggest that the methylester, hydrolysis catalyzed by CheB proceeds through a mechanism involving a, serine nucleophile. The methylesterase active site is tentatively, identified as a cleft at the C-terminal edge of the beta-sheet containing, residues Ser164, His190 and Asp286. The three-dimensional fold, and the, arrangement of residues within the catalytic triad distinguishes the CheB, methylesterase from any previously described serine protease or serine, hydrolase.
About this Structure
1CHD is a Single protein structure of sequence from Salmonella typhimurium. Active as Protein-glutamate methylesterase, with EC number 3.1.1.61 Full crystallographic information is available from OCA.
Reference
Crystal structure of the catalytic domain of the chemotaxis receptor methylesterase, CheB., West AH, Martinez-Hackert E, Stock AM, J Mol Biol. 1995 Jul 7;250(2):276-90. PMID:7608974
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