1f4l
From Proteopedia
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CRYSTAL STRUCTURE OF THE E.COLI METHIONYL-TRNA SYNTHETASE COMPLEXED WITH METHIONINE
Overview
Amino acid selection by aminoacyl-tRNA synthetases requires efficient, mechanisms to avoid incorrect charging of the cognate tRNAs. A, proofreading mechanism prevents Escherichia coli methionyl-tRNA synthetase, (EcMet-RS) from activating in vivo L-homocysteine, a natural competitor of, L-methionine recognised by the enzyme. The crystal structure of the, complex between EcMet-RS and L-methionine solved at 1.8 A resolution, exhibits some conspicuous differences with the recently published free, enzyme structure. Thus, the methionine delta-sulphur atom replaces a water, molecule H-bonded to Leu13N and Tyr260O(eta) in the free enzyme., Rearrangements of aromatic residues enable the protein to form a, hydrophobic pocket around the ligand side-chain. The subsequent formation, of an extended water molecule network contributes to relative, displacements, up to 3 A, of several domains of the protein. The structure, of this complex supports a plausible mechanism for the selection of, L-methionine versus L-homocysteine and suggests the possibility of, information transfer between the different functional domains of the, enzyme.
About this Structure
1F4L is a Single protein structure of sequence from Escherichia coli with ZN and MET as ligands. Active as Methionine--tRNA ligase, with EC number 6.1.1.10 Full crystallographic information is available from OCA.
Reference
How methionyl-tRNA synthetase creates its amino acid recognition pocket upon L-methionine binding., Serre L, Verdon G, Choinowski T, Hervouet N, Risler JL, Zelwer C, J Mol Biol. 2001 Mar 2;306(4):863-76. PMID:11243794
Page seeded by OCA on Tue Nov 20 14:36:41 2007
Categories: Escherichia coli | Methionine--tRNA ligase | Single protein | Chonowski, T. | Hervouet, N. | Serre, L. | Verdon, G. | Zelwer, C. | MET | ZN | Amino acid | Rossman fold | Trna | Zinc domain
