Structural insights into transcription activation of the Streptomyces antibiotic regulatory protein, AfsR

Autor: Jing Shi, Zonghang Ye, Zhenzhen Feng, Aijia Wen, Lu Wang, Zhipeng Zhang, Liqiao Xu, Qian Song, Fulin Wang, Tianyu Liu, Shuang Wang, Yu Feng, Wei Lin
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: iScience, Vol 27, Iss 8, Pp 110421- (2024)
Druh dokumentu: article
ISSN: 2589-0042
DOI: 10.1016/j.isci.2024.110421
Popis: Summary: The Streptomyces antibiotic regulatory proteins (SARPs) are ubiquitously distributed transcription activators in Streptomyces and control antibiotics biosynthesis and morphological differentiation. However, the molecular mechanism behind SARP-dependent transcription initiation remains elusive. We here solve the cryo-EM structure of an AfsR-loading RNA polymerase (RNAP)-promoter intermediate complex (AfsR-RPi) including the Streptomyces coelicolor RNAP, a large SARP member AfsR, and its target promoter DNA that retains the upstream portion straight. The structure reveals that one dimeric N-terminal AfsR-SARP domain (AfsR-SARP) specifically engages with the same face of the AfsR-binding sites by the conserved DNA-binding domains (DBDs), replacing σHrdBR4 to bind the suboptimal −35 element, and shortens the spacer between the −10 and −35 elements. Notably, the AfsR-SARPs also recruit RNAP through extensively interacting with its conserved domains (β flap, σHrdBR4, and αCTD). Thus, these macromolecular snapshots support a general model and provide valuable clues for SARP-dependent transcription activation in Streptomyces.
Databáze: Directory of Open Access Journals