8E8M

Mycobacterium tuberculosis RNAP paused elongation complex

Summary for 8E8M

• Entry DOI: 10.2210/pdb8e8m/pdb
• EMDB information: 27944
• Descriptor: DNA (54-MER), RNA (42-MER), DNA-directed RNA polymerase subunit alpha, ... (9 entities in total)
• Functional Keywords: rna polymerase, transcription factor, elongation, pausing, transcription-transferase-dna complex, transcription-dna-rna complex, transcription/dna/rna
• Biological source: Mycobacterium tuberculosis; More
• Total number of polymer chains: 8
• Total formula weight: 410548.25

Authors

Delbeau, M.,Darst, S.A.,Campbell, E.A. (deposition date: 2022-08-25, release date: 2023-03-22, Last modification date: 2025-05-14)

Primary citation

Delbeau, M.,Omollo, E.O.,Froom, R.,Koh, S.,Mooney, R.A.,Lilic, M.,Brewer, J.J.,Rock, J.,Darst, S.A.,Campbell, E.A.,Landick, R.
Structural and functional basis of the universal transcription factor NusG pro-pausing activity in Mycobacterium tuberculosis.
Mol.Cell, 83:1474-1488.e8, 2023

PubMed Abstract: Transcriptional pauses mediate regulation of RNA biogenesis. DNA-encoded pause signals trigger pausing by stabilizing RNA polymerase (RNAP) swiveling and inhibiting DNA translocation. The N-terminal domain (NGN) of the only universal transcription factor, NusG/Spt5, modulates pausing through contacts to RNAP and DNA. Pro-pausing NusGs enhance pauses, whereas anti-pausing NusGs suppress pauses. Little is known about pausing and NusG in the human pathogen Mycobacterium tuberculosis (Mtb). We report that MtbNusG is pro-pausing. MtbNusG captures paused, swiveled RNAP by contacts to the RNAP protrusion and nontemplate-DNA wedged between the NGN and RNAP gate loop. In contrast, anti-pausing Escherichia coli (Eco) NGN contacts the MtbRNAP gate loop, inhibiting swiveling and pausing. Using CRISPR-mediated genetics, we show that pro-pausing NGN is required for mycobacterial fitness. Our results define an essential function of mycobacterial NusG and the structural basis of pro- versus anti-pausing NusG activity, with broad implications for the function of all NusG orthologs.

PubMed: 37116494
DOI: 10.1016/j.molcel.2023.04.007

Experimental method

ELECTRON MICROSCOPY (3.13 Å)