title: Mechanism of Transcription Termination by RNA Polymerase III Utilizes a Non-template Strand Sequence-Specific Signal Element.
abstract: Understanding the mechanism of transcription termination by a eukaryotic RNA polymerase (RNAP) has been limited by lack of a characterizable intermediate that reflects transition from an elongation complex to a true termination event. While other multisubunit RNAPs require multipartite cis-signals and/or ancillary factors to mediate pausing and release of the nascent transcript from the clutches of these enzymes, RNAP III does so with precision and efficiency on a simple oligo(dT) tract, independent of other cis-elements or trans-factors. We report an RNAP III pre-termination complex that reveals termination mechanisms controlled by sequence-specific elements in the non-template strand. Furthermore, the TFIIF-like RNAP III subunit C37 is required for this function of the non-template strand signal. The results reveal the RNAP III terminator as an information-rich control element. While the template strand promotes destabilization via a weak oligo(rU:dA) hybrid, the non-template strand provides distinct sequence-specific destabilizing information through interactions with the C37 subunit.
authors.affiliation: Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
authors.forename: Aneeshkumar G
authors.initials: AG
authors.lastname: Arimbasseri
authors.affiliation: Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA; Commissioned Corps, US Public Health Service. Electronic address: maraiar@mail.nih.gov.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Maraia
mesh_terms: D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D008957:Models, Genetic; D011485:Protein Binding; D012320:RNA Polymerase III / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D013728:Terminator Regions, Genetic / Q000235:genetics; D061806:Transcription Termination, Genetic
chemical_list: D004271:DNA, Fungal; D012322:RNA Precursors; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; C508371:RPC11 protein, S cerevisiae; C508372:RPC37 protein, S cerevisiae; C508373:RPC53 protein, S cerevisiae; D012320:RNA Polymerase III