1xu4

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spinqualitylabelsall models 1xu4, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

ATPASE IN COMPLEX WITH AMP-PNP, MAGNESIUM AND POTASSIUM CO-F

Overview

Homologous gene recombination is crucial for the repair of DNA. A, superfamily of recombinases facilitate a central strand exchange reaction, in the repair process. This reaction is initiated by coating, single-stranded DNA (ssDNA) with recombinases in the presence of ATP and, Mg(2+) co-factors to form helical nucleoprotein filaments with elevated, ATPase and strand invasion activities. At the amino acid sequence level, archaeal RadA and Rad51 and eukaryal Rad51 and meiosis-specific DMC1 form, a closely related group of recombinases distinct from bacterial RecA., Unlike the extensively studied Escherichia coli RecA (EcRecA), increasing, evidences on yeast and human recombinases imply that their optimal, activities are dependent on the presence of a monovalent cation, particularly potassium. Here we present the finding that archaeal RadA, from Methanococcus voltae (MvRadA) is a stringent potassium-dependent, ATPase, and the crystal structure of this protein in complex with the, non-hydrolyzable ATP analog adenosine 5'-(beta,gamma-iminotriphosphate), Mg(2+), and K(+) at 2.4 A resolution. Potassium triggered an in situ, conformational change in the ssDNA-binding L2 region concerted with, incorporation of two potassium ions at the ATPase site in the RadA, crystals preformed in K(+)-free medium. Both potassium ions were observed, in contact with the gamma-phosphate of the ATP analog, implying a direct, role by the monovalent cations in stimulating the ATPase activity., Cross-talk between the ATPase site and the ssDNA-binding L2 region, visualized in the MvRadA structure provides an explanation to the, co-factor-induced allosteric effect on RecA-like recombinases.

About this Structure

1XU4 is a Single protein structure of sequence from Methanococcus voltae with MG, K and ANP as ligands. Full crystallographic information is available from OCA.

Reference

Crystal structure of an ATPase-active form of Rad51 homolog from Methanococcus voltae. Insights into potassium dependence., Wu Y, Qian X, He Y, Moya IA, Luo Y, J Biol Chem. 2005 Jan 7;280(1):722-8. Epub 2004 Nov 10. PMID:15537659

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