title: Inhibition of single and double-stranded DNA-dependent ATPase of RecA protein by ATP ribose-modified analogs.
abstract: The single-stranded (SS) DNA-dependent ATP hydrolysis at pH 7.5 and 6.2 and the double-stranded (DS) DNA-dependent ATP hydrolysis at pH 6.2 by recA protein (no reaction was detectable at pH 7.5) were found to be inhibited competitively by ribose-modified analogs of ATP, 3'-0-anthraniloyl-ATP (Ant-ATP) and 3'-0-(N-methylanthraniloyl)- ATP (Mant-ATP). The Ki values for Ant-ATP and Mant-ATP is SS DNA-dependent hydrolysis were about 8 and 5 microns at pH 7.5 and 12 and 10 microns at pH 6.2. For the DS DNA-dependent hydrolysis, the Ki values for Ant-ATP and Mant-ATP were about 7 and 6 microns. All these Ki values were much smaller than those of ADP which is also a competitive inhibitor for the ATPase activity of the recA protein. Ant-ATP and Mant-ATP caused a reduction in the Hill coefficients for ATP in SS DNA-dependent ATP hydrolysis at pH 7.5 and DS DNA-dependent hydrolysis. These observations showed that the ATP analogs which have a bulky substituent in the ribose moiety of ATP had strong hydrophobic interactions with the ATP binding site on the recA protein and also contributed to the cooperative effect of ATP.
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D004265:DNA Helicases; D004277:DNA, Single-Stranded / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D011938:Rec A Recombinases / Q000378:metabolism*; D062367:ortho-Aminobenzoates / Q000494:pharmacology*
chemical_list: D004277:DNA, Single-Stranded; D062367:ortho-Aminobenzoates; C045472:3'-O-anthraniloyl ATP; C045473:3'-O-(N-methylanthraniloyl) ATP; D000255:Adenosine Triphosphate; D011938:Rec A Recombinases; D000251:Adenosine Triphosphatases; D004265:DNA Helicases