title: The Walker A motif mutation recA4159 abolishes the SOS response and recombination in a recA730 mutant of Escherichia coli.
abstract: In bacteria, the RecA protein forms recombinogenic filaments required for the SOS response and DNA recombination. In order to form a recombinogenic filament, wild type RecA needs to bind ATP and to interact with mediator proteins. The RecA730 protein is a mutant version of RecA with superior catalytic abilities, allowing filament formation without the help of mediator proteins. The mechanism of RecA730 filament formation is not well understood, and the question remains as to whether the RecA730 protein requires ATP binding in order to become competent for filament formation. We examined two mutants, recA730,4159 (presumed to be defective for ATP binding) and recA730,2201 (defective for ATP hydrolysis), and show that they have different properties with respect to SOS induction, conjugational recombination and double-strand break repair. We show that ATP binding is essential for all RecA730 functions, while ATP hydrolysis is required only for double-strand break repair. Our results emphasize the similarity of the SOS response and conjugational recombination, neither of which requires ATP hydrolysis by RecA730.
authors.affiliation: Laboratory of Evolutionary Genetics, Department of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address: asimatov@irb.hr.
authors.forename: Ana
authors.initials: A
authors.lastname: Šimatović
authors.affiliation: Laboratory of Evolutionary Genetics, Department of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia; Institute for Research and Development of Sustainable Ecosystems, Faculty of Veterinary Medicine, Heinzelova 55, 10000 Zagreb, Croatia. Electronic address: pmitrik@irb.hr.
authors.forename: Petar T
authors.initials: PT
authors.lastname: Mitrikeski
authors.affiliation: Laboratory of Evolutionary Genetics, Department of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address: ivlasic@irb.hr.
authors.forename: Ignacija
authors.initials: I
authors.lastname: Vlašić
authors.affiliation: Laboratory of Evolutionary Genetics, Department of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address: msopta@irb.hr.
authors.forename: Mary
authors.initials: M
authors.lastname: Sopta
authors.affiliation: Laboratory of Evolutionary Genetics, Department of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address: brcic@irb.hr.
authors.forename: Krunoslav
authors.initials: K
authors.lastname: Brčić-Kostić
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D004260:DNA Repair; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D013014:SOS Response, Genetics
chemical_list: D050505:Mutant Proteins; D000255:Adenosine Triphosphate; D011938:Rec A Recombinases
keywords: ATP binding; Filament formation; RecA730 protein