1f4l
From Proteopedia
(New page: 200px<br /><applet load="1f4l" size="450" color="white" frame="true" align="right" spinBox="true" caption="1f4l, resolution 1.85Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1f4l.jpg|left|200px]]<br /><applet load="1f4l" size=" | + | [[Image:1f4l.jpg|left|200px]]<br /><applet load="1f4l" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1f4l, resolution 1.85Å" /> | caption="1f4l, resolution 1.85Å" /> | ||
'''CRYSTAL STRUCTURE OF THE E.COLI METHIONYL-TRNA SYNTHETASE COMPLEXED WITH METHIONINE'''<br /> | '''CRYSTAL STRUCTURE OF THE E.COLI METHIONYL-TRNA SYNTHETASE COMPLEXED WITH METHIONINE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Amino acid selection by aminoacyl-tRNA synthetases requires efficient | + | 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== | ==About this Structure== | ||
| - | 1F4L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ZN and MET as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Methionine--tRNA_ligase Methionine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.10 6.1.1.10] Full crystallographic information is available from [http:// | + | 1F4L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=MET:'>MET</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Methionine--tRNA_ligase Methionine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.10 6.1.1.10] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F4L OCA]. |
==Reference== | ==Reference== | ||
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[[Category: zinc domain]] | [[Category: zinc domain]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:34:50 2008'' |
Revision as of 10:34, 21 February 2008
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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 and 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 Thu Feb 21 12:34:50 2008
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
