1mea: Difference between revisions

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

Methionyl-tRNA synthetase from Escherichia coli contains one tightly bound zinc atom per subunit. The region encompassing residues 138 to 163 of this enzyme is responsible for the metal binding. A 28-mer peptide corresponding to these residues was expressed in vivo and shown to contain approximately 1 mol of tightly bound Zn/mol of peptide. In this study, the three-dimensional solution structure of this peptide was solved by means of two-dimensional proton NMR spectroscopy. A total of 133 nuclear Overhauser effect distance constraints and 22 dihedral angle restraints were used for the calculations, using a hybrid distance-geometry-simulated annealing strategy. Excluding the first four residues, the resulting structure is well-defined (r.m.s.d. 0.71 A for backbone atoms) and composed of a series of four tight turns. The second and the fourth turns are composed of CXXC sequences which are structurally homologous to the NH-S turns found in the metal binding sites of gag retroviral proteins and rubredoxin. The solution structure of the zinc binding peptide shows significant discrepancies with the crystal structure of methionyl-tRNA synthetase.

1MEA 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> as [http://en.wikipedia.org/wiki/ligand ligand]. 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=1MEA OCA].  

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