Abstract
Conjugational recombination in wild-type Escherichia coli K-12 depends on the products of a large number of genes. In the wild type, three of these genes have been identified: recA (Clark and Margulies 1965), recB (Howard-Flanders and Theriot 1966), and recC (Emmerson and Howard-Flanders 1967). Mutations in either recB or recC do not result in complete recombination deficiency, and suppression by sbcA (Barbour et al. 1970) and sbcB (Kushner et al. 1971) mutations have led to the discovery of other recombination genes. Against the recB recC sbcB multiple-mutant background, mutations in the following genes were detected by reduction in conjugational recombination frequencies: recA (Horii and Clark 1973), recF (Horii and Clark 1973), recJ (Lovett and Clark 1984), recN (Lloyd et al. 1983), and ruv (Lloyd et al. 1984; S. Lovett and A.J. Clark, unpubl.). Against the recB recC sbcA multiple-mutant background, mutations in the following genes were similarly detected: recA (Gillen...