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1ynu
From Proteopedia
Crystal structure of apple ACC synthase in complex with L-vinylglycine
Overview
L-Vinylglycine (L-VG) is both a substrate for and a mechanism-based inhibitor of 1-aminocyclopropane-1-carboxylate (ACC) synthase. The ratio of the rate constants for catalytic conversion to alpha-ketobutyrate and ammonia to inactivation is 500/1. The crystal structure of the covalent adduct of the inactivated enzyme was determined at 2.25 Angstroms resolution. The active site contains an external aldimine of the adduct of L-VG with the pyridoxal 5'-phosphate cofactor. The side chain gamma-carbon of L-VG is covalently bound to the epsilon-amino group of Lys273. This species corresponds to one of the two alternatives proposed by Feng and Kirsch [Feng, L. and Kirsch, J.F. (2000) L-Vinylglycine is an alternative substrate as well as a mechanism-based inhibitor of 1-aminocyclopropane-1-carboxylate synthase. Biochemistry 39, 2436-2444] and presumably results from Michael addition to a vinylglycine ketimine intermediate.
About this Structure
1YNU is a Single protein structure of sequence from Malus x domestica. Full crystallographic information is available from OCA.
Reference
Structure of ACC synthase inactivated by the mechanism-based inhibitor L-vinylglycine., Capitani G, Tschopp M, Eliot AC, Kirsch JF, Grutter MG, FEBS Lett. 2005 Apr 25;579(11):2458-62. PMID:15848188 Page seeded by OCA on Sat May 3 16:33:35 2008
