Bacteriophage T4 RNA Ligase is Gene 63 Product, the Protein that Promotes Tail Fiber Attachment to the Baseplate

• Published in: Proceedings of the National Academy of Sciences - PNAS 1977-08, Vol.74 (8), p.3355-3359
• Main Authors: Snopek, Thomas J., Wood, William B., Conley, M. Patricia, Chen, Peter, Cozzarelli, Nicholas R.
• Format: Article
• Language: English
• Subjects: Bacteriophage T4; Bacteriophages; Coliphages - enzymology; DNA; DNA-Directed DNA Polymerase - metabolism; Enzymes; Escherichia coli - enzymology; Genes, Viral; Genetic mutation; Infections; Kinetics; Ligation; Mutation; Nucleic acids; Polynucleotide Ligases - metabolism; Protein Denaturation; Reagents; RNA; RNA Ligase (ATP) - genetics; RNA Ligase (ATP) - isolation & purification; RNA Ligase (ATP) - metabolism; Viral Proteins - genetics; Viral Proteins - metabolism; Virus Replication
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.74.8.3355

RNA ligase and tail fiber attachment activities, normally induced following bacteriophage T4 infection of Escherichia coli, are not induced when gene 63 amber mutants of T4 infect nonpermissive host cells. Both activities are induced when these mutants infect permissive hosts, or when revertants of these mutants infect nonpermissive hosts. When one of these mutants infects a host that carries supF, both activities are more than normally heat labile. RNA ligase, purified to homogeneity, promotes the tail fiber attachment reaction in vitro with a specific activity similar to that of the most highly purified preparations of gene 63 product isolated on the basis of tail fiber attachment activity. We conclude that T4 RNA ligase is gene 63 product. The RNA ligase and tail fiber attachment reactions differ in requirements and in response to some inhibitors, suggesting that the two activities of the gene 63 product may be mechanistically unrelated.