T4 bacteriophage-coded polynucleotide kinase and RNA ligase are involved in host tRNA alteration or repair

T4-induced polynucleotide kinase, RNA ligase, and a tRNA-specific endonuclease were previously implicated in host tRNA breakage and reunion. to examine this hypothesis we followed the fate of host tRNAs in T4-infected Escherichia coli CTr5x, a strain restricting phage mutants lacking polynucleotide kinase (pnk^-) or RNA ligase (rli^-). Two host tRNA species which were cleaved in the anticodon loops were further processed in the wild type but not in the mutant infections, indicating that polynucleotide kinase and RNA ligase are involved in the alteration or repair of these E. coli Ctr5× tRNA species.