Open AccessInteractions of RecF protein with RecO, RecR, and single-stranded DNA binding proteins reveal roles for the RecF–RecO–RecR complex in DNA repair and recombination
Author(s) -
Shrikanth P. Hegde,
Ming Hui Qin,
Xin Hui Li,
Mark A. Atkinson,
Alvin J. Clark,
Malini Rajagopalan,
Murty V. V. S. Madiraju
Publication year - 1996
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.93.25.14468
Subject(s) - biology , dna , microbiology and biotechnology , genetics
The products of therecF, recO, andrecR genes are thought to interact and assist RecA in the utilization of single-stranded DNA precomplexed with single-stranded DNA binding protein (Ssb) during synapsis. Using immunoprecipitation, size-exclusion chromatography, and Ssb protein affinity chromatography in the absence of any nucleotide cofactors, we have obtained the following results: (i ) RecF interacts with RecO, (ii ) RecF interacts with RecR in the presence of RecO to form a complex consisting of RecF, RecO, and RecR (RecF–RecO–RecR); (iii ) RecF interacts with Ssb protein in the presence of RecO. These data suggested that RecO mediates the interactions of RecF protein with RecR and with Ssb proteins. Incubation of RecF, RecO, RecR, and Ssb proteins resulted in the formation of RecF–RecO–Ssb complexes; i.e., RecR was excluded. Preincubation of RecF, RecO, and RecR proteins prior to addition of Ssb protein resulted in the formation of complexes consisting of RecF, RecO, RecR, and Ssb proteins. These data suggest that one role of RecF is to stabilize the interaction of RecR with RecO in the presence of Ssb protein. Finally, we found that interactions of RecF with RecO are lost in the presence of ATP. We discuss these results to explain how the RecF–RecO–RecR complex functions as an anti-Ssb factor.