Figure 1.

Immunoprecipitation of RecF, RecO, and RecR proteins by RecF antibodies. RecF, RecO, and RecR proteins (each at 6 μM) in various combinations were mixed in buffer I containing 35 mM Tris·HCl (pH 7.5), 10 mM MgCl2, 1 mM DTT, and 100 mM NaCl. RecF antibodies were added, incubated for 30 min on ice followed by the addition of protein A-agarose beads. Samples were then incubated at 4°C with gentle rocking for 10 min. Protein A-agarose-bound antigen–antibody complexes were separated from free proteins by centrifugation at 12,000 × g for 10 min followed by washing three times in buffer I. Samples were resuspended in Laemmli buffer, and proteins were separated on SDS/polyacrylamide gels and visualized by staining with Coomassie blue. Protein combinations used in these experiments are indicated.