A vaccinia virus late transcription factor with biochemical and molecular identity to a human cellular protein.
A factor designated VLTF-X is required to support vaccinia virus late transcription in vitro. It has been found that a late promoter DNA binding activity cochromatographs and cosediments with VLTF-X activity. Current experiments show that VLTF-X activity is present in a variety of uninfected mammalian cell types and is indistinguishable from that recovered from infected cells based upon several criteria. VLTF-X activity from both sources displays the same purification profile over phosphocellulose and DNA affinity resins and has the same sedimentation coefficient. In addition, the factors purified from both infected and uninfected cells form protein-DNA complexes of identical electrophoretic mobility in the presence of vaccinia virus late promoter-containing DNA. The affinity of these factors for the late promoter probes is identical and late promoter-specific based on competition experiments. Moreover, VLTF-X purified from both sources bound to late promoter-containing DNA in the presence or absence of MgCl2 and ATP and formed complexes resistant to heat inactivation. These experiments offer proof that vaccinia virus factor VLTF-X is a host cell protein that supports transcription of the viral late genes.
Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
S K
SK
Gunasinghe
A E
AE
Hubbs
C F
CF
Wright
D000255:Adenosine Triphosphate / Q000494:pharmacology; D001483:Base Sequence; D002413:Cations, Divalent / Q000494:pharmacology; D002474:Cell-Free System; D002846:Chromatography, Affinity; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000187:drug effects; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic; D014616:Vaccinia virus / Q000235:genetics*; D014764:Viral Proteins / Q000302:isolation & purification / Q000378:metabolism*
D002413:Cations, Divalent; D009363:Neoplasm Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D000255:Adenosine Triphosphate