6XII

Escherichia coli transcription-translation complex B (TTC-B) containing an 24 nt long mRNA spacer, NusG, and fMet-tRNAs at E-site and P-site

This is a non-PDB format compatible entry.

Summary for 6XII

• Entry DOI: 10.2210/pdb6xii/pdb
• EMDB information: 22192
• Descriptor: 50S ribosomal protein L21, E-site and P-site tRNA (fMet), DNA-directed RNA polymerase subunit beta, ... (67 entities in total)
• Functional Keywords: transcription-translation complex, transcription/translation
• Biological source: Escherichia coli; More
• Total number of polymer chains: 67
• Total formula weight: 2740433.73

Authors

Molodtsov, V.,Wang, C.,Su, M.,Ebright, R.H. (deposition date: 2020-06-20, release date: 2020-09-02, Last modification date: 2024-10-16)

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 (7 Å)