The roles of the lambda c3 gene and the Escherichia coli catabolite gene activation system in the establishment of lysogeny by bacteriophage lambda.

Maximum lysogenization of E. coli by bacteriophage lambda requires both the lambdacIII gene function and the host catabolite gene activation system mediated by adenosine 3':5'-cyclic monophosphate. Whereas considerable lysogenization occurs in the presence of either system alone, lysogenization is absolutely prevented in the absence of both systems. Neither system is, however, required for efficient lysogenization when the host bears an hfl(-) mutation. It is argued that the normal function of these two systems is to negate the antagonistic effect of the Hfl(+) protein upon lysogenization. It is further argued that both the lambdacIII gene function and the Hfl(+) protein do not directly affect the host catabolite gene activation system.