In vitro premature termination in SV40 late transcription.
Nuclear extracts and viral transcribing minichromosomes were prepared from SV40-infected cells and incubated in vitro with [alpha-32P]UTP under conditions which allow the elongation of preinitiated RNA chains. Sucrose gradient lysis of the transcription mixtures revealed two populations of SV40-specific RNA: elongating chains that remain associated with the viral minichromosomes, and, at the top of the gradient, small free RNA detached from the template and hybridizing exclusively to the promoter-proximal region of SV40 DNA. This free RNA was shown by polyacrylamide gel electrophoresis to comprise essentially a 94 nucleotide species, which could, however, at high UTP concentration, be elongated a further few nucleotides before terminating. These results thus show that the actively transcribing minichromosomes provide a sytem in which the attenuated RNA can be released from the template. Moreover, this is the first demonstration of specific in vitro termination of polymerase B transcription. The conditions which lead to transcription termination are discussed.
Pfeiffer
P
P
Department of Genetics, Weizmann Institute of Science, Rehovot, Israel.
Hay
N
N
Pruzan
R
R
Jakobovits
E B
EB
Aloni
Y
Y
D000818:Animals; D001665:Binding Sites; D002457:Cell Extracts; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012313:RNA / Q000096:biosynthesis; D012367:RNA, Viral / Q000737:chemistry; D013539:Simian virus 40 / Q000235:genetics*; D013698:Templates, Genetic; D014158:Transcription, Genetic; D014542:Uridine Monophosphate
D002457:Cell Extracts; D012367:RNA, Viral; D012313:RNA; D014542:Uridine Monophosphate