title: PcrA-mediated disruption of RecA nucleoprotein filaments--essential role of the ATPase activity of RecA.
abstract: The essential DNA helicase, PcrA, regulates recombination by displacing the recombinase RecA from the DNA. The nucleotide-bound state of RecA determines the stability of its nucleoprotein filaments. Using single-molecule fluorescence approaches, we demonstrate that RecA displacement by a translocating PcrA requires the ATPase activity of the recombinase. We also show that in a 'head-on collision' between a polymerizing RecA filament and a translocating PcrA, the RecA K72R ATPase mutant, but not wild-type RecA, arrests helicase translocation. Our findings demonstrate that translocation of PcrA is not sufficient to displace RecA from the DNA and assigns an essential role for the ATPase activity of RecA in helicase-mediated disruption of its filaments.
authors: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
authors: Matt V
authors: MV
authors: Fagerburg
authors: Grant D
authors: GD
authors: Schauer
authors: Karen R
authors: KR
authors: Thickman
authors: Piero R
authors: PR
authors: Bianco
authors: Saleem A
authors: SA
authors: Khan
authors: Sanford H
authors: SH
authors: Leuba
authors: Syam P
authors: SP
authors: Anand
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D001411:Geobacillus stearothermophilus / Q000201:enzymology; D021381:Protein Transport; D011938:Rec A Recombinases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004277:DNA, Single-Stranded; C084217:pcrA protein, Bacteria; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D011938:Rec A Recombinases; D000251:Adenosine Triphosphatases; D004265:DNA Helicases