title: Suppression of a mutation in gene 3 of bacteriophage T7 (T7 endonuclease I) by mutations in phage and host polynucleotide ligase.
abstract: Bacteriophage T7 bearing amber mutations in both gene 1.3 (T7 DNA ligase) and gene 3 (T7 endonuclease I) are viable when grown in suppressor-negative, ligase-negative hosts. This is evidenced by a high plating efficiency and a large burst size compared to the single mutants. These findings may be explained by a limited destruction of cellular DNA by the double mutant.
mesh_terms: D002250:Carbon Radioisotopes; D002499:Centrifugation, Density Gradient; D003090:Coliphages / Q000201:enzymology* / Q000254:growth & development; D003433:Crosses, Genetic; D004269:DNA, Bacterial / Q000378:metabolism; D004720:Endonucleases / Q000096:biosynthesis*; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D009154:Mutation; D011118:Polynucleotide Ligases / Q000096:biosynthesis*; D013489:Suppression, Genetic; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014779:Virus Replication
chemical_list: D002250:Carbon Radioisotopes; D004269:DNA, Bacterial; D014316:Tritium; D004720:Endonucleases; D011118:Polynucleotide Ligases; D013936:Thymidine