Enzymatic characterization of a mutant of Escherichia coli with an altered DNA ligase.
A temperature-sensitive, radiation-sensitive mutant of Escherichia coli has been assayed for DNA ligase activity in vitro. The strain contains a markedly reduced amount of DNA-joining activity, which is thermolabile. The formation of the ligase-adenylate intermediate is also temperature-sensitive in vitro. Two temperature-resistant revertants of the mutant contain normal amounts of a thermostable ligase. The mutant is killed by growth at 42 degrees C, a temperature at which it displays aberrant DNA synthesis. These results suggest that the ligase is necessary for normal DNA metabolism and viability in this strain.
D000227:Adenine Nucleotides / Q000096:biosynthesis; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004492:Edetic Acid; D004926:Escherichia coli / Q000201:enzymology*; D005827:Genetics, Microbial; D006358:Hot Temperature; D008025:Ligases / Q000378:metabolism*; D009154:Mutation; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
D000227:Adenine Nucleotides; D004269:DNA, Bacterial; D014316:Tritium; D004492:Edetic Acid; D008025:Ligases; D013936:Thymidine