期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：16
页码：6068-6073
DOI：10.1073/pnas.0401393101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We identify Rpa12p of RNA polymerase I (Pol I) as a termination factor. Combined analyses using transcription run-on, electron microscopy-visualized chromatin spreading and RT-PCR have been applied to the rRNA-encoding genes of Saccharomyces cerevisiae. These confirm that Pol I termination occurs close to the Reb1p-dependent terminator in wild-type strains. However, deletion mutants for the 3' end-processing enzyme Rnt1p or the Rpa12p subunit of Pol I both show Pol I transcription in the spacer. For {Delta}rpa12, these spacer polymerases are devoid of nascent transcripts, suggesting they are immediately degraded. The homology of Rpa12p to the small subunit Rpb9p of Pol II and Rpc11p of Pol III, both implicated in transcriptional termination, points to a common termination mechanism for all three classes of RNA polymerase.
