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-Structure paper
タイトル | Crl activates transcription by stabilizing active conformation of the master stress transcription initiation factor. |
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ジャーナル・号・ページ | Elife, Vol. 8, Year 2019 |
掲載日 | 2019年12月17日 |
![]() | Juncao Xu / Kaijie Cui / Liqiang Shen / Jing Shi / Lingting Li / Linlin You / Chengli Fang / Guoping Zhao / Yu Feng / Bei Yang / Yu Zhang / ![]() |
PubMed 要旨 | σ is a master transcription initiation factor that protects bacterial cells from various harmful environmental stresses including antibiotic pressure. Although its mechanism remains unclear, it is ...σ is a master transcription initiation factor that protects bacterial cells from various harmful environmental stresses including antibiotic pressure. Although its mechanism remains unclear, it is known that full activation of σ-mediated transcription requires a σ-specific activator, Crl. In this study, we determined a 3.80 Å cryo-EM structure of an transcription activation complex ( Crl-TAC) comprising σ-RNA polymerase (σ-RNAP) holoenzyme, Crl, and a nucleic-acid scaffold. The structure reveals that Crl interacts with domain 2 of σ (σ) and the RNAP core enzyme, but does not contact promoter DNA. Results from subsequent hydrogen-deuterium exchange mass spectrometry (HDX-MS) indicate that Crl stabilizes key structural motifs within σ to promote the assembly of the σ-RNAP holoenzyme and also to facilitate formation of an RNA polymerase-promoter DNA open complex (RPo). Our study demonstrates a unique DNA contact-independent mechanism of transcription activation, thereby defining a previously unrecognized mode of transcription activation in cells. |
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手法 | EM (単粒子) |
解像度 | 3.8 Å |
構造データ | |
化合物 | ![]() ChemComp-ZN: ![]() ChemComp-MG: |
由来 |
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![]() | TRANSCRIPTION / RNA polymerase / Escherichia coli / Crl / transcription activation / transcription initiation / transcription regulator / sigma S |