[2][3] The RecF pathway begins when RecJ, an exonuclease that cleaves single-stranded DNA in the 5 → 3′ direction, binds to the 5' end of a single-strand gap in DNA and starts moving upstream while cleaving the 5' strand.
Although RecJ can function without them, single-strand binding protein (SSBP) and the RecQ helicase greatly increase how much the 5' is cut back.
When present, SSBP binds to the 3' overhang remaining after RecJ finishes cutting back the 5' strand.
RecFOR then loads RecA onto a recessed 5' end of this ssDNA-dsDNA junction.
The RecR subunit in RecFR then interacts with RecO to form the RecFOR complex.