8I23

Clostridium thermocellum RNA polymerase transcription open complex with SigI1 and its promoter

Summary for 8I23

• Entry DOI: 10.2210/pdb8i23/pdb
• EMDB information: 35130
• Descriptor: DNA-directed RNA polymerase subunit alpha, DNA-directed RNA polymerase subunit beta, DNA-directed RNA polymerase subunit beta', ... (9 entities in total)
• Functional Keywords: transcription open complex, sigi, transcription, transcription-dna complex, transcription/dna
• Biological source: Acetivibrio thermocellus DSM1313; More
• Total number of polymer chains: 8
• Total formula weight: 431903.36

Authors

Li, J.,Zhang, H.,Li, D.,Feng, Y.,Zhu, P. (deposition date: 2023-01-13, release date: 2023-10-11, Last modification date: 2023-11-01)

Primary citation

Li, J.,Zhang, H.,Li, D.,Liu, Y.J.,Bayer, E.A.,Cui, Q.,Feng, Y.,Zhu, P.
Structure of the transcription open complex of distinct sigma I factors.
Nat Commun, 14:6455-6455, 2023

PubMed Abstract: Bacterial σ factors of the σ-family are widespread in Bacilli and Clostridia and are involved in the heat shock response, iron metabolism, virulence, and carbohydrate sensing. A multiplicity of σ paralogues in some cellulolytic bacteria have been shown to be responsible for the regulation of the cellulosome, a multienzyme complex that mediates efficient cellulose degradation. Here, we report two structures at 3.0 Å and 3.3 Å of two transcription open complexes formed by two σ factors, SigI1 and SigI6, respectively, from the thermophilic, cellulolytic bacterium, Clostridium thermocellum. These structures reveal a unique, hitherto-unknown recognition mode of bacterial transcriptional promoters, both with respect to domain organization and binding to promoter DNA. The key characteristics that determine the specificities of the σ paralogues were further revealed by comparison of the two structures. Consequently, the σ factors represent a distinct set of the σ-family σ factors, thus highlighting the diversity of bacterial transcription.

PubMed: 37833284
DOI: 10.1038/s41467-023-41796-4

Experimental method

ELECTRON MICROSCOPY (3.03 Å)