The effect of bacteriophage T2 infection on the synthesis of transfer RNA in Escherichia coli

Abstract

During the initial 5 minutes of T2 bacteriophage infection of Escherichia coli, there is substantial incorporation of labeled guanine into the transfer RNA (tRNA) fraction, strongly suggesting that new tRNA is synthesized early in infection. In this 5-minute period the amount of labeled guanine incorporated into the tRNA fraction of T2-infected bacteria is 23% of that in uninfected bacteria during an equivalent period. The tRNA fractions from T2-infected bacteria and uninfected bacteria were compared by pulse-labeling cultures of each for 5 minutes with 3H and 14C isotopes of guanine and partially resolving a mixture of the doubly labeled tRNA species by reversed phase chromatography. The chromatographic pattern of the labeled tRNA from uninfected cultures of E. coli was very similar to that of nonlabeled carrier tRNA from uninfected cultures. tRNA prepared from pulse-labeled T2-infected cultures of E. coli had a chromatographic pattern that was radically different from that of tRNA prepared from uninfected cultures. These results indicate either that the tRNA synthesized after T2 infection of E. coli represents species of tRNA entirely different from those made in uninfected bacteria, or that relative proportions of the different species made are greatly altered after phage infection, some being made preferentially and others in reduced amounts. Evidence is presented that a substantial amount of the material in the tRNA fraction made during T2 infection can accept amino acids.