Control of gene function in bacteriophage Tr. 3. Preventing the shutoff of early enzyme synthesis.

Synthesis of early T4 protein, which is normally shut off at 10 min after infection, continues until lysis when host cells have been preinfected with T3 sam(+). In host cells preinfected with T3 sam(-), synthesis of early enzymes is shut off as normal. Thus, S-adenosylmethionine is required for the turnoff of early T4 functions (at least when host cells have been preinfected with T3).