+Search query
-Structure paper
Title | Crl activates transcription by stabilizing active conformation of the master stress transcription initiation factor. |
---|---|
Journal, issue, pages | Elife, Vol. 8, Year 2019 |
Publish date | Dec 17, 2019 |
Authors | Juncao Xu / Kaijie Cui / Liqiang Shen / Jing Shi / Lingting Li / Linlin You / Chengli Fang / Guoping Zhao / Yu Feng / Bei Yang / Yu Zhang / |
PubMed Abstract | 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. |
External links | Elife / PubMed:31846423 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.8 Å |
Structure data | |
Chemicals | ChemComp-ZN: ChemComp-MG: |
Source |
|
Keywords | TRANSCRIPTION / RNA polymerase / Escherichia coli / Crl / transcription activation / transcription initiation / transcription regulator / sigma S |