6VU3

Cryo-EM structure of Escherichia coli transcription-translation complex A (TTC-A) containing mRNA with a 12 nt long spacer

This is a non-PDB format compatible entry.

Summary for 6VU3

• Entry DOI: 10.2210/pdb6vu3/pdb
• EMDB information: 21386
• Descriptor: 50S ribosomal protein L21, E-site and A-site tRNA (fMet), DNA-directed RNA polymerase subunit beta, ... (66 entities in total)
• Functional Keywords: bacterial coupled transcription-translation complex, ribosome, transcription-translation complex
• Biological source: Escherichia coli; More
• Total number of polymer chains: 66
• Total formula weight: 2667324.92

Authors

Molodtsov, V.,Wang, C.,Su, M.,Ebright, R. (deposition date: 2020-02-14, release date: 2020-09-02, Last modification date: 2024-11-13)

Primary citation

Wang, C.,Molodtsov, V.,Firlar, E.,Kaelber, J.T.,Blaha, G.,Su, M.,Ebright, R.H.
Structural basis of transcription-translation coupling.
Science, 369:1359-1365, 2020

PubMed Abstract: In bacteria, transcription and translation are coupled processes in which the movement of RNA polymerase (RNAP)-synthesizing messenger RNA (mRNA) is coordinated with the movement of the first ribosome-translating mRNA. Coupling is modulated by the transcription factors NusG (which is thought to bridge RNAP and the ribosome) and NusA. Here, we report cryo-electron microscopy structures of transcription-translation complexes (TTCs) containing different-length mRNA spacers between RNAP and the ribosome active-center P site. Structures of TTCs containing short spacers show a state incompatible with NusG bridging and NusA binding (TTC-A, previously termed "expressome"). Structures of TTCs containing longer spacers reveal a new state compatible with NusG bridging and NusA binding (TTC-B) and reveal how NusG bridges and NusA binds. We propose that TTC-B mediates NusG- and NusA-dependent transcription-translation coupling.

PubMed: 32820061
DOI: 10.1126/science.abb5317

Experimental method

ELECTRON MICROSCOPY (3.7 Å)