EMD-21476

Single-particle
9.9 Å
EMD-21476 Deposition: 27/02/2020
Map released: 02/09/2020
Last modified: 23/10/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-21476

Escherichia coli transcription-translation complex C5 (TTC-C5) containing mRNA with a 21 nt long spacer, NusG, and fMet-tRNAs at E-site and P-site

EMD-21476

Single-particle
9.9 Å
EMD-21476 Deposition: 27/02/2020
Map released: 02/09/2020
Last modified: 23/10/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Escherichia coli, synthetic construct
Sample: Escherichia coli transcription-translation complex C5 (TTC-C5) containing mRNA with a 21 nt long spacer, NusG, and fMet-tRNAs at E-site and P-site
Fitted models: 6vyy (Avg. Q-score: 0.034)

Deposition Authors: Molodtsov V , Wang C
Structural basis of transcription-translation coupling.
Wang C , Molodtsov V , Firlar E , Kaelber JT , Blaha G , Su M , Ebright RH
(2020) Science , 369 , 1359 - 1365
PUBMED: 32820061
DOI: doi:10.1126/science.abb5317
ISSN: 1095-9203
ASTM: SCIEAS
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 Escherichia coli 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.