1ynu: Difference between revisions

[[Image:1ynu.gif|left|200px]]<br /><applet load="1ynu" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1YNU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Malus_x_domestica Malus x domestica] with <scene name='pdbligand=NI:'>NI</scene>, <scene name='pdbligand=K:'>K</scene>, <scene name='pdbligand=PY4:'>PY4</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/1-aminocyclopropane-1-carboxylate_synthase 1-aminocyclopropane-1-carboxylate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.4.1.14 4.4.1.14] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YNU OCA].  

[[Category: Eliot, A C.]]

[[Category: Grutter, M G.]]

[[Category: Kirsch, J F.]]

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