title: Transcription of orthopoxvirus telomeres at late times during infection.
abstract: The telomeres of orthopoxvirus DNAs consists largely of short repeated sequences organized into at least two separate sets. Although the sequence composition of the orthopoxvirus telomeres is highly conserved, these regions do not appear to encode any proteins. At late times during infection, the telomeres of vaccinia virus are transcribed. A promoter in the region between the two sets of repeats directs transcription towards the hairpin-loop end of the viral DNA. This promoter resembles the promoters of other poxvirus late genes, and directs the synthesis of RNAs whose structure is consistent with the presence of 5' poly(A) sequences typical of late RNAs. The lengths of these late transcripts suggest that some transcription extends through the hairpin-loop region. This might occur either when the genome is in a monomeric form or when the genome is in the concatemeric form of the DNA replication intermediate. The function of late transcription of the telomeres is unclear, but similar transcription of the telomeres of vaccinia virus, cowpox virus, and raccoonpox virus suggests that such transcription may have a role in viral replication.
authors.affiliation: Department of Microbiology and Immunology, Duke University Medical Center, Durham, North Carolina 27710.
authors.forename: B L
authors.initials: BL
authors.lastname: Parsons
authors.forename: D J
authors.initials: DJ
authors.lastname: Pickup
mesh_terms: D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D005814:Genes, Viral; D007739:L Cells; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D010957:Plasmids; D011212:Poxviridae / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic; D015347:RNA Probes; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D015345:Oligonucleotide Probes; D015347:RNA Probes; D012333:RNA, Messenger; D012367:RNA, Viral; D015719:Single-Strand Specific DNA and RNA Endonucleases