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-Structure paper
タイトル | Structural basis of RNA polymerase III transcription initiation. |
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ジャーナル・号・ページ | Nature, Vol. 553, Issue 7688, Page 301-306, Year 2018 |
掲載日 | 2018年1月17日 |
著者 | Guillermo Abascal-Palacios / Ewan Phillip Ramsay / Fabienne Beuron / Edward Morris / Alessandro Vannini / |
PubMed 要旨 | RNA polymerase (Pol) III transcribes essential non-coding RNAs, including the entire pool of transfer RNAs, the 5S ribosomal RNA and the U6 spliceosomal RNA, and is often deregulated in cancer cells. ...RNA polymerase (Pol) III transcribes essential non-coding RNAs, including the entire pool of transfer RNAs, the 5S ribosomal RNA and the U6 spliceosomal RNA, and is often deregulated in cancer cells. The initiation of gene transcription by Pol III requires the activity of the transcription factor TFIIIB to form a transcriptionally active Pol III preinitiation complex (PIC). Here we present electron microscopy reconstructions of Pol III PICs at 3.4-4.0 Å and a reconstruction of unbound apo-Pol III at 3.1 Å. TFIIIB fully encircles the DNA and restructures Pol III. In particular, binding of the TFIIIB subunit Bdp1 rearranges the Pol III-specific subunits C37 and C34, thereby promoting DNA opening. The unwound DNA directly contacts both sides of the Pol III cleft. Topologically, the Pol III PIC resembles the Pol II PIC, whereas the Pol I PIC is more divergent. The structures presented unravel the molecular mechanisms underlying the first steps of Pol III transcription and also the general conserved mechanisms of gene transcription initiation. |
リンク | Nature / PubMed:29345637 |
手法 | EM (単粒子) |
解像度 | 3.3 - 4.0 Å |
構造データ | EMDB-3955, PDB-6eu0: EMDB-3956: RNA Polymerase III - open DNA complex (OC-POL3) EMDB-3959: |
化合物 | ChemComp-ZN: ChemComp-MG: |
由来 |
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キーワード | TRANSCRIPTION / RNA Pol III / promoter opening |