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Bacteriophage T4 anticodon nuclease, polynucleotide kinase and RNA ligase reprocess the host lysine tRNA.
Author(s) -
Amitsur M.,
Levitz R.,
Kaufmann G.
Publication year - 1987
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1987.tb02532.x
Subject(s) - tel aviv , rna ligase , biology , transfer rna , pseudouridine , polynucleotide , dna ligase , rna , microbiology and biotechnology , biochemistry , dna , library science , gene , computer science
Host tRNAs cleaved near the anticodon occur specifically in T4‐infected Escherichia coli prr strains which restrict polynucleotide kinase (pnk) or RNA ligase (rli) phage mutants. The cleavage products are transient with wt but accumulate in pnk‐ or rli‐ infections, implicating the affected enzymes in repair of the damaged tRNAs. Their roles in the pathway were elucidated by comparing the mutant infection intermediates with intact tRNA counterparts before or late in wt infection. Thus, the T4‐induced anticodon nuclease cleaves lysine tRNA 5′ to the wobble position, yielding 2′:3′‐P greater than and 5′‐OH termini. Polynucleotide kinase converts them into a 3′‐OH and 5′ P pair joined in turn by RNA ligase. Presumably, lysine tRNA depletion, in the absence of polynucleotide kinase and RNA ligase mediated repair, underlies prr restriction. However, the nuclease, kinase and ligase may benefit T4 directly, by adapting levels or decoding specificities of host tRNAs to T4 codon usage.