The Initiation of T4 Deoxyribonucleic Acid-dependent β-Glucosyltransferase Synthesis in Vitro

Bacteriophage T4 DNA was used in vitro as a template for RNA and protein synthesis with ribosomes and supernatant enzymes prepared from uninfected Escherichia coli. Protein synthesis in this system was previously shown to result in synthesis de novo of an enzymatically active β-glucosyltransferase, an early T4-specific protein not detectable in uninfected cells. E. coli cells treated with trimethoprim were used to prepare extracts with decreased levels of N10-formyltetrahydrofolic acid. T4 DNA-dependent β-glucosyltransferase synthesis in such systems was stimulated markedly both by exogenously added folinic acid and by purified N-formylmethionyl transfer RNA. These experiments suggest that early enzyme synthesis in T4-infected cells utilizes the same chain initiator as the uninfected host. E. coli cells infected with T4 were found to retain preinfection levels of formylmethionine-specific tRNA as well as the enzymes needed to charge and formylate that species of tRNA.