6FLQ

CryoEM structure of E.coli RNA polymerase paused elongation complex bound to NusA

Summary for 6FLQ

• Entry DOI: 10.2210/pdb6flq/pdb
• EMDB information: 4275
• Descriptor: DNA-directed RNA polymerase subunit alpha, ZINC ION, DNA-directed RNA polymerase subunit beta, ... (10 entities in total)
• Functional Keywords: rna polymerase, transcriptional pausing, his pause, nusa, transcription
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 9
• Total formula weight: 472856.20

Authors

Guo, X.,Weixlbaumer, A. (deposition date: 2018-01-26, release date: 2018-03-21, Last modification date: 2024-05-15)

Primary citation

Guo, X.,Myasnikov, A.G.,Chen, J.,Crucifix, C.,Papai, G.,Takacs, M.,Schultz, P.,Weixlbaumer, A.
Structural Basis for NusA Stabilized Transcriptional Pausing.
Mol. Cell, 69:816-827.e4, 2018

PubMed Abstract: Transcriptional pausing by RNA polymerases (RNAPs) is a key mechanism to regulate gene expression in all kingdoms of life and is a prerequisite for transcription termination. The essential bacterial transcription factor NusA stimulates both pausing and termination of transcription, thus playing a central role. Here, we report single-particle electron cryo-microscopy reconstructions of NusA bound to paused E. coli RNAP elongation complexes with and without a pause-enhancing hairpin in the RNA exit channel. The structures reveal four interactions between NusA and RNAP that suggest how NusA stimulates RNA folding, pausing, and termination. An asymmetric translocation intermediate of RNA and DNA converts the active site of the enzyme into an inactive state, providing a structural explanation for the inhibition of catalysis. Comparing RNAP at different stages of pausing provides insights on the dynamic nature of the process and the role of NusA as a regulatory factor.

PubMed: 29499136
DOI: 10.1016/j.molcel.2018.02.008

Experimental method

ELECTRON MICROSCOPY (3.6 Å)