1zm5

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spinqualitylabelsall models 1zm5, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Conjugative Relaxase TRWC in complex with ORIT dna, cooper-bound structure

Overview

TrwC is a DNA strand transferase that catalyzes the initial and final, stages of conjugative DNA transfer. We have solved the crystal structure, of the N-terminal relaxase domain of TrwC in complex with a 27 base-long, DNA oligonucleotide that contains both the recognition hairpin and the, scissile phosphate. In addition, a series of ternary structures of, protein-DNA complexes with different divalent cations at the active site, have been solved. Systematic anomalous difference analysis allowed us to, determine unambiguously the nature of the metal bound. Zn2+, Ni2+ and Cu2+, were found to bind the histidine-triad metal binding site. Comparison of, the structures of the different complexes suggests two pathways for the, DNA to exit the active pocket. They are probably used at different steps, of the conjugative DNA-processing reaction. The structural information, allows us to propose (i) an enzyme mechanism where the scissile phosphate, is polarized by the metal ion facilitating the nucleophilic attack of the, catalytic tyrosine, and (ii) a probable sequence of events during, conjugative DNA processing that explains the biological function of the, relaxase.

About this Structure

1ZM5 is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.

Reference

Unveiling the molecular mechanism of a conjugative relaxase: The structure of TrwC complexed with a 27-mer DNA comprising the recognition hairpin and the cleavage site., Boer R, Russi S, Guasch A, Lucas M, Blanco AG, Perez-Luque R, Coll M, de la Cruz F, J Mol Biol. 2006 May 5;358(3):857-69. Epub 2006 Feb 28. PMID:16540117

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