Control of lysogenization by phage P22 II. Mutations ( clyA) in the c1 gene that cause increased lysogenization

Abstract

P22 cly mutants lysogenize at very high frequency after infection of wild-type Salmonella. One class of P22 cly mutations, clyA mutations, are shown to map within the P22 c1 gene and to increase the activity of the c1 gene product during establishment of lysogeny. The P22 clyA mutations also appear to affect c2-repressor gene expression in cis and to cause a Cro − phenotype, despite the fact that the clyA mutations map far downstream (with respect to transcription) of the end of the P22 cro gene.