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-Structure paper
タイトル | Structures of an RNA polymerase promoter melting intermediate elucidate DNA unwinding. |
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ジャーナル・号・ページ | Nature, Vol. 565, Issue 7739, Page 382-385, Year 2019 |
掲載日 | 2019年1月9日 |
著者 | Hande Boyaci / James Chen / Rolf Jansen / Seth A Darst / Elizabeth A Campbell / |
PubMed 要旨 | A key regulated step of transcription is promoter melting by RNA polymerase (RNAP) to form the open promoter complex. To generate the open complex, the conserved catalytic core of the RNAP combines ...A key regulated step of transcription is promoter melting by RNA polymerase (RNAP) to form the open promoter complex. To generate the open complex, the conserved catalytic core of the RNAP combines with initiation factors to locate promoter DNA, unwind 12-14 base pairs of the DNA duplex and load the template-strand DNA into the RNAP active site. Formation of the open complex is a multi-step process during which transient intermediates of unknown structure are formed. Here we present cryo-electron microscopy structures of bacterial RNAP-promoter DNA complexes, including structures of partially melted intermediates. The structures show that late steps of promoter melting occur within the RNAP cleft, delineate key roles for fork-loop 2 and switch 2-universal structural features of RNAP-in restricting access of DNA to the RNAP active site, and explain why clamp opening is required to allow entry of single-stranded template DNA into the active site. The key roles of fork-loop 2 and switch 2 suggest a common mechanism for late steps in promoter DNA opening to enable gene expression across all domains of life. |
リンク | Nature / PubMed:30626968 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.55 - 4.4 Å |
構造データ | EMDB-9037, PDB-6edt: EMDB-9039, PDB-6ee8: |
化合物 | ChemComp-ZN: ChemComp-MG: ChemComp-C0L: |
由来 |
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キーワード | TRANSCRIPTION/DNA / initiation / transcription bubble / closed clamp / open promoter complex / TRANSCRIPTION / TRANSCRIPTION-DNA complex / half bubble / intermediate |