title: Biochemical and genetic characterization of vaccinia virus temperature-sensitive mutants with DNA- and DNAf-phenotypes.
abstract: Eighty temperature-sensitive (ts) mutants of vaccinia virus were examined for defects in synthesis of DNA. Nine ts mutants were incapable of synthesizing DNA at the restrictive temperature of 39.5 degrees C (DNA- mutants). Biochemical and genetic data indicate that all 9 DNA- mutants carry mutations in different genes. Temperature shift-up experiments have shown that 6 ts mutants with the DNA- phenotype have mutations in the genes coding for the proteins directly associated with vaccinia DNA synthesis. Temperature shift-down experiments in the presence of cytosine arabinoside revealed 5 ts mutants capable of synthesizing DNA at the elevated temperature, but this DNA failed to form infectious virions. These ts mutants were designated as DNAf- mutants. Pulse-chase experiments for the DNAf- mutant 1877 revealed that viral DNA produced at 39.5 degrees C was incapable of entering into mature virions or any subviral particles. Based on the data for recombination among ts mutants with the DNA- and DNAf- phenotype a tentative genetic map was constructed.
mesh_terms: D003513:Cycloheximide / Q000494:pharmacology; D004279:DNA, Viral / Q000096:biosynthesis* / Q000502:physiology; D005814:Genes, Viral; D005816:Genetic Complementation Test; D009154:Mutation; D010641:Phenotype; D011995:Recombination, Genetic; D013696:Temperature; D014616:Vaccinia virus / Q000235:genetics* / Q000378:metabolism
chemical_list: D004279:DNA, Viral; D003513:Cycloheximide