Cloning of the uvrC gene of Escherichia coli: expression of a DNA repair gene.

We have cloned the uvrC gene of Escherichia coli, using an F' plasmid carrying the uvrC region as a source of DNA. Two plasmids, pSC101 and pBR322, were used as cloning vectors. The recombinant plasmids were selected for their ability to complement the uvrC defect of E. coli strains AB1884 and N177. We conclude that the uvrC structural gene is contained in a 1.9-kilobase DNA fragment. The protein encoded by the uvrC gene appears to have a monomer molecular weight of 64,500 as analyzed by denaturing polyacrylamide gel electrophoresis. Strains containing multicopy uvrC+ plasmids overproduce a factor that is missing in lysates of uvrC- mutants and required for an in vitro model repair reaction. The expression of uvrC+ hybrid plasmids suggests that the structural gene is separated by at least 0.8 kilobase from the regulatory region.