title: RecA protein-promoted cleavage of LexA repressor in the presence of ADP and structural analogues of inorganic phosphate, the fluoride complexes of aluminum and beryllium.
abstract: Complexes formed from A13+ or Be2+ and fluoride inhibit the single-stranded DNA-dependent ATPase activity of RecA protein. In contrast, poly(dT)-RecA-ADP complexes, which are inactive for cleavage of LexA protein, become fully active in the presence of AlF4- or BeF3- ions. These data suggest that fluoride complexes of aluminum and beryllium (called herein X) convert RecA-ADP complexes, which bind weakly to single-stranded DNA, into RecA-ADP-X complexes, which bind tightly to single-stranded DNA, the ADP-X moiety behaving as a nonhydrolyzable analogue of ATP. We propose that AlF4- and BeF3- ions act as analogues of inorganic phosphate by binding to the site of the gamma-phosphate of ATP on RecA-ADP complexes, hence mimicking the single-stranded DNA-RecA-ADP-Pi transition state. We conclude that the elementary reaction that switches RecA protein from a high affinity single-stranded DNA binding state to a low affinity single-stranded DNA binding state is not ATP hydrolysis per se but Pi release.
authors.affiliation: Laboratory of Enzymology, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
authors.forename: P L
authors.initials: PL
authors.lastname: Moreau
authors.forename: M F
authors.initials: MF
authors.lastname: Carlier
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000535:Aluminum / Q000494:pharmacology*; D017607:Aluminum Compounds; D001426:Bacterial Proteins / Q000378:metabolism*; D001608:Beryllium / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005459:Fluorides / Q000494:pharmacology*; D005461:Fluorine / Q000494:pharmacology*; D007700:Kinetics; D008962:Models, Theoretical; D010710:Phosphates / Q000494:pharmacology; D011938:Rec A Recombinases / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D012697:Serine Endopeptidases; D014157:Transcription Factors / Q000378:metabolism*; D000099160:LexA Repressor Protein
chemical_list: D000244:Adenosine Diphosphate; D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate; D000535:Aluminum; D017607:Aluminum Compounds; D001426:Bacterial Proteins; D001608:Beryllium; D005459:Fluorides; D005461:Fluorine; D010710:Phosphates; D011938:Rec A Recombinases; D012097:Repressor Proteins; D012697:Serine Endopeptidases; D014157:Transcription Factors; D000099160:LexA Repressor Protein; C056920:beryllium trifluoride; C050992:tetrafluoroaluminate