8K60

Cryo-EM structure of Streptomyces coelicolor transcription initiation complex with the global transcription factor AfsR

Summary for 8K60

• Entry DOI: 10.2210/pdb8k60/pdb
• EMDB information: 36914
• Descriptor: DNA-directed RNA polymerase subunit alpha, ZINC ION, DNA-directed RNA polymerase subunit beta, ... (10 entities in total)
• Functional Keywords: transcription factor, transcription-dna complex, gene regulation
• Biological source: Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145); More
• Total number of polymer chains: 11
• Total formula weight: 697769.12

Authors

Lin, W.,Shi, J. (deposition date: 2023-07-24, release date: 2024-07-31, Last modification date: 2024-08-21)

Primary citation

Shi, J.,Ye, Z.,Feng, Z.,Wen, A.,Wang, L.,Zhang, Z.,Xu, L.,Song, Q.,Wang, F.,Liu, T.,Wang, S.,Feng, Y.,Lin, W.
Structural insights into transcription activation of the Streptomyces antibiotic regulatory protein, AfsR.
Iscience, 27:110421-110421, 2024

PubMed Abstract: The antibiotic regulatory proteins (SARPs) are ubiquitously distributed transcription activators in 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 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 σR4 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, σR4, and αCTD). Thus, these macromolecular snapshots support a general model and provide valuable clues for SARP-dependent transcription activation in .

PubMed: 39108719
DOI: 10.1016/j.isci.2024.110421

Experimental method

ELECTRON MICROSCOPY (3.4 Å)