The recF gene is required for two basic genetic processes, genetic recombination and DNA repair. The major question about recF function centers on whether recF functions in a regulatory capacity controlling these processes or whether it has an enzymatic function needed to carry out these reactions. Our studies of suppression of recF by several recA mutations suggests that the recF gene product functions primarily by modulating recA activity. It appears that two recF dependent changes in recA activity normally occur in response to DNA damage. The first change results in activation of the recA dependent proteolytic activity required for induction of the SOS pathways of DNA repair. The second change allows recA to carry out the RecF pathway of recombination and recombinational DNA repair. These two changes in recA activity are separable by mutation since the srfA mutation of the recA gene results in restoration of only RecF recombination without concomitant restoration of SOS induction in recF mutant strains.