Overproduction of SSB protein enhances the capacity for photorepair in Escherichia coli recA cells

We studied photoreactivation in cells carrying the multicopy ssb+ plasmid. These cells overproduce single-stranded DNA-binding protein (SSB). Overproduction of SSB enhances the capacity for photoreactivation in recA bacteria but not in the recA+ background. It is suggested that, in recA cells, SSB binds to the dimer region of DNA and that this binding stimulates the process of photoreactivation. In recA+ cells, the same stimulation might be achieved by RecA protein. (author)