The major late adenovirus type-2 transcription unit: Termination is downstream from the last poly(A) site
Late in adenovirus type-2 infection of HeLa cells the majority of viral RNA synthesis occurs from a transcription unit that extends between 16% and 100% on the physical map of the Ad-2† † Abbreviations used: Ad-2, adenovirus type-2; u.v., ultraviolet irradiation. genome. Poly(A) is added to RNA at five distinct sites within the transcription unit (Fraser & Ziff, 1978; Nevins & Darnell, 1978a,b). As many as 13 different messenger RNAs can be processed from the primary RNA transcripts of this region of the genome (Chow et al., 1977a,b; Nevins & Darnell, 1978a). Examination of nuclear RNA in several different types of experiments (RNA "fingerprint" studies and hybridization of pulse-labeled "nascent" RNA and labeled nuclear RNA synthesized after ultraviolet irradiation to an ordered set of restriction endonuclease-generated DNA fragments) indicates that the mRNA 3′ terminus most distant from the promoter does not correspond to the RNA polymerase termination site for the transcription unit. Transcription, continues ~2500 to 3000 residues beyond the 3′ terminus of the most promoter distal mRNA (localized between co-ordinates 89.7 and 91.9) and into the region 98.2-100 on the Ad-2 physical map. The occurrence of RNA termination sites distal to the poly(A) site is discussed as a general feature of transcriptional unit design in animal cells. © 1979.
Fraser, NW; Nevins, JR; Ziff, E; Jr, JED
Volume / Issue
Start / End Page
International Standard Serial Number (ISSN)