Preferential binding of Escherichia coli RecF protein to gapped DNA in the presence of adenosine (gamma-thio) triphosphate.
Escherichia coli RecF protein binds, but does not hydrolyze, ATP. To determine the role that ATP binding to RecF plays in RecF protein-mediated DNA binding, we have determined the interaction between RecF protein and single-stranded (ss)DNA, double-stranded (ds)DNA, and dsDNA containing ssDNA regions (gapped [g]DNA) either alone or in various combinations both in the presence and in the absence of adenosine (gamma-thio) triphosphate, gamma-S-ATP, a nonhydrolyzable ATP analog. Protein-DNA complexes were analyzed by electrophoresis on agarose gels and visualized by autoradiography. The type of protein-DNA complexes formed in the presence of gamma-S-ATP was different with each of the DNA substrates and from those formed in the absence of gamma-S-ATP. Competition experiments with various combinations of DNA substrates indicated that RecF protein preferentially bound gDNA in the presence of gamma-S-ATP, and the order of preference of binding was gDNA > dsDNA > ssDNA. Since gDNA has both ds- and ssDNA components, we suggest that the role for ATP in RecF protein-DNA interactions in vivo is to confer specificity of binding to dsDNA-ssDNA junctions, which is necessary for catalyzing DNA repair and recombination.
Department of Microbiology, University of Texas Health Center at Tyler 75710, USA.
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Hegde
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Rajagopalan
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MV
Madiraju
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D001667:Binding, Competitive; D004247:DNA / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D011485:Protein Binding
D001426:Bacterial Proteins; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C489340:recF protein, E coli; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D004247:DNA; C066218:recF protein, Bacteria