DNA-binding proteins in the cytoplasm of vaccinia virus-infected mouse L-cells

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Abstract
Mouse L-cell fibroblasts were infected with vaccinia virus and labeled 2-3 h postinfection with [35S]methionine. Labeled proteins were fractionated on native and denatured DNA-cellulose columns and then analyzed by sodium dodecyl sulfate[SDS]-polyacrylamide gel electrophoresis. Twenty-four vaccinia DNA-binding polypeptides (VDP), ranging in MW from 90,000-12,500, were detected. VDP-12A (MW 29,750) had affinity for denatured but not native DNA, and its synthesis was dependent on viral DNA replication. VDP-20 (MW 41,000) bound very tightly to native and denatured DNA and was displaced only after boiling the protein-DNA-cellulose matrix in 1% SDS. VDP-8, -11, -12, -13 and -14 behaved electrophoretically like the polypeptide species previously shown to be present in DNA-protein complexes prepared from infected cells. The MW of VDP-10 (50,000), VDP-11 (36,000) and VDP-8 (67,000) were similar to the polypeptide subunits of polyadenylate polymerase and phosphohydrolase I, enzymes purified from virions which were also shown to have affinity for DNA.