The RecF protein antagonizes RecX function via direct interaction.
The RecX protein inhibits RecA filament extension, leading to net filament disassembly. The RecF protein physically interacts with the RecX protein and protects RecA from the inhibitory effects of RecX. In vitro, efficient RecA filament formation onto single-stranded DNA binding protein (SSB)-coated circular single-stranded DNA (ssDNA) in the presence of RecX occurs only when all of the RecFOR proteins are present. The RecOR proteins contribute only to RecA filament nucleation onto SSB-coated single-stranded DNA and are unable to counter the inhibitory effects of RecX on RecA filaments. RecF protein uniquely supports substantial RecA filament extension in the presence of RecX. In vivo, RecF protein counters a RecX-mediated inhibition of plasmid recombination. Thus, a significant positive contribution of RecF to RecA filament assembly is to antagonize the effects of the negative modulator RecX, specifically during the extension phase.
Lusetti
Shelley L
SL
Department of Biochemistry, University of Wisconsin, Madison, Madison, Wisconsin 53706, USA.
Hobbs
Michael D
MD
Stohl
Elizabeth A
EA
Chitteni-Pattu
Sindhu
S
Inman
Ross B
RB
Seifert
H Steven
HS
Cox
Michael M
MM
D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism / Q000648:ultrastructure; D004277:DNA, Single-Stranded / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011995:Recombination, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C081006:RecO protein, E coli; C489318:RecR protein, E coli; C430523:RecX protein, Xanthomonas campestris; C489340:recF protein, E coli