1ynu
From Proteopedia
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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 with NI, K, PY4 and TRS as ligands. Active as 1-aminocyclopropane-1-carboxylate synthase, with EC number 4.4.1.14 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 Wed Nov 21 06:56:17 2007
