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-Structure paper
タイトル | Cryo-EM structure of σ RNA polymerase and promoter DNA complex revealed a role of σ non-conserved region during the open complex formation. |
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ジャーナル・号・ページ | J Biol Chem, Vol. 293, Issue 19, Page 7367-7375, Year 2018 |
掲載日 | 2018年5月11日 |
著者 | Anoop Narayanan / Frank S Vago / Kunpeng Li / M Zuhaib Qayyum / Dinesh Yernool / Wen Jiang / Katsuhiko S Murakami / |
PubMed 要旨 | First step of gene expression is transcribing the genetic information stored in DNA to RNA by the transcription machinery including RNA polymerase (RNAP). In , a primary σ factor forms the RNAP ...First step of gene expression is transcribing the genetic information stored in DNA to RNA by the transcription machinery including RNA polymerase (RNAP). In , a primary σ factor forms the RNAP holoenzyme to express housekeeping genes. The σ contains a large insertion between the conserved regions 1.2 and 2.1, the σ non-conserved region (σ), but its function remains to be elucidated. In this study, we determined the cryo-EM structures of the RNAP σ holoenzyme and its complex with promoter DNA (open complex, RPo) at 4.2 and 5.75 Å resolutions, respectively, to reveal native conformations of RNAP and DNA. The RPo structure presented here found an interaction between the σ and promoter DNA just upstream of the -10 element, which was not observed in a previously determined RNAP transcription initiation complex (RPo plus short RNA) structure by X-ray crystallography because of restraint of crystal packing effects. Disruption of the σ and DNA interaction by the amino acid substitutions (R157A/R157E) influences the DNA opening around the transcription start site and therefore decreases the transcription activity of RNAP. We propose that the σ and DNA interaction is conserved in proteobacteria, and RNAP in other bacteria replaces its role with a transcription factor. |
リンク | J Biol Chem / PubMed:29581236 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 4.25 - 5.75 Å |
構造データ | |
化合物 | ChemComp-MG: ChemComp-ZN: |
由来 |
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キーワード | TRANSCRIPTION / Escherichia coli / RNA polymerase / transcription/dna / transcription-dna complex |