1ynu
From Proteopedia
Crystal structure of apple ACC synthase in complex with L-vinylglycine
Structural highlights
Function1A1C_MALDO Catalyzes the formation of 1-aminocyclopropane-1-carboxylate, a direct precursor of ethylene in higher plants. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedL-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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|