[Physical mapping of DNA-temperature-sensitive mutations of vaccinia virus].

Four DNA-temperature-sensitive (ts) mutations were mapped in the genome of vaccinia virus (VV). Physical mapping of these mutations was performed by restriction analysis of the genomes of recombinants between VV DNA- ts mutants and ectromelia virus as well as by the marker rescue with cloned restriction fragments of VV DNA. One of the mutations was mapped on the HindIII-E-fragment. Biochemical studies of this mutant indicate that the mutation is not in the DNA polymerase gene which is located on the same fragment. The other three mutations were mapped in a 10 kilobase region in the middle of the HindIII-D-fragment. As shown previously, these mutations inactivate different genes, and the products of these genes participate directly in the DNA synthesis. Thus, at least three proteins involved in the VV DNA synthesis are encoded by neighboring genes in the central part of the viral genome.