title: Location of the ss--mutation of bacteriophage T7 in genes 10, the structural gene for the major capsid protein.
abstract: T7+ phage are unable to plate on a strain of Shigella sonnei D2 371-48. Spontaneous phage mutants arise (ss--mutants) that are able to plate on this strain of Shigella. We have shown by complementation studies and genetic crosses that the ss--mutation maps in gene 10, the structural gene for the major protein of the capsid. This finding implies that the gene 10 protein may interact with a host protein during phage development and that the abortive infection of T7 observed in S. sonnei D2 371-48 with T7+ phage may be a defect in head morphogenesis. Our studies also reveal that various T7 strains commonly contain deletions in nonessential regions. T7 ss--mutants selected after growth of T7+ on Shigella D2 371-48 often acquire a deletion in the 0.7 gene that is not necessary for the ss--phenotype. Finally, we have found a new nonessential region of the T7 chromosome that is located between 33 and 35.5% of the T7 genome length.
mesh_terms: D002213:Capsid / Q000096:biosynthesis*; D002874:Chromosome Mapping; D003090:Coliphages / Q000032:analysis / Q000254:growth & development / Q000378:metabolism*; D004279:DNA, Viral / Q000032:analysis; D005796:Genes; D005816:Genetic Complementation Test; D009154:Mutation; D010641:Phenotype; D012764:Shigella sonnei; D013696:Temperature; D014764:Viral Proteins / Q000096:biosynthesis*
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins