Temperature-sensitive mutant in the vaccinia virus E6 protein produce virions that are transcriptionally inactive.
The vaccinia virus E6R gene encodes a late protein that is packaged into virion cores. A temperature-sensitive mutant was used to study the role of this protein in viral replicative cycle. Cts52 has a P226L missense mutation in the E6R gene, shows a two-log reduction in plaque formation, but displays normal patterns of gene expression, late protein processing and DNA replication during infection. Mutant virions produced at 40 degrees C were similar in their morphology to wt virions grown at 40 degrees C. The particle to infectivity ratio was 50 times higher in purified Cts52 grown at 40 degrees C when compared to the mutant grown at permissive temperature. In vitro characterization of Cts-52 particles grown at 40 degrees C revealed no differences in protein composition or in DNA content and the mutant virions could bind and enter cells. However, core particles prepared from Cts52 grown at 40 degrees C failed to transcribe in vitro. Our results show that E6 in the virion has either a direct or an indirect role in viral transcription.
Boyd
Olga
O
Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA.
Strahl
Audra L
AL
Rodeffer
Carson
C
Condit
Richard C
RC
Moussatche
Nissin
N
D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D006358:Hot Temperature; D009154:Mutation; D014158:Transcription, Genetic; D014616:Vaccinia virus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014758:Viral Core Proteins / Q000235:genetics / Q000378:metabolism*; D010948:Viral Plaque Assay; D014771:Virion / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D053585:Virus Attachment; D053586:Virus Internalization; D014779:Virus Replication
D004279:DNA, Viral; D014758:Viral Core Proteins