title: RNA polymerase-associated protein Rap94 confers promoter specificity for initiating transcription of vaccinia virus early stage genes.
abstract: The association of a 94,000-Da viral polypeptide, called Rap94, with 30-40% of the multisubunit DNA-dependent RNA polymerase molecules purified from infectious vaccinia virus particles was established by immunoaffinity chromatography. The submolar amount of Rap94, relative to RNA polymerase, was confirmed by quantitative immunoblotting of total virion extracts. Only the RNA polymerase molecules containing Rap94 could functionally interact with VETF, the vaccinia virus early transcription factor, to transcribe a double-stranded DNA template regulated by a viral early stage promoter. Rap94 was required for the synthesis of short oligoribonucleotides and for the formation of stable ternary transcription complexes. With a nonspecific single-stranded DNA template, however, the Rap94-deficient polymerase had greater catalytic activity than the Rap94-containing polymerase. These data support a model in which Rap94 confers specificity to the RNA polymerase for promoters of early stage genes.
authors.affiliation: Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: B Y
authors.initials: BY
authors.lastname: Ahn
authors.forename: P D
authors.initials: PD
authors.lastname: Gershon
authors.forename: B
authors.initials: B
authors.lastname: Moss
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D002846:Chromatography, Affinity; D012321:DNA-Directed RNA Polymerases / Q000302:isolation & purification / Q000378:metabolism*; D017781:Genes, Immediate-Early; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014616:Vaccinia virus / Q000235:genetics*; D014764:Viral Proteins / Q000302:isolation & purification / Q000378:metabolism*; D014771:Virion / Q000201:enzymology
chemical_list: C085819:RAP94 protein, Vaccinia virus; D014157:Transcription Factors; D014764:Viral Proteins; C064449:early transcription factor protein, Vaccinia virus; D012321:DNA-Directed RNA Polymerases