| Autor: |
Juncao Xu, Kaijie Cui, Liqiang Shen, Jing Shi, Lingting Li, Linlin You, Chengli Fang, Guoping Zhao, Yu Feng, Bei Yang, Yu Zhang |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
eLife, Vol 8 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
2050-084X |
| DOI: |
10.7554/eLife.50928 |
| Popis: |
σS 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 σS-mediated transcription requires a σS-specific activator, Crl. In this study, we determined a 3.80 Å cryo-EM structure of an Escherichia coli transcription activation complex (E. coli Crl-TAC) comprising E. coli σS-RNA polymerase (σS-RNAP) holoenzyme, Crl, and a nucleic-acid scaffold. The structure reveals that Crl interacts with domain 2 of σS (σS2) 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 σS2 to promote the assembly of the σS-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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
