EMD-11725

Single-particle
4.2 Å
EMD-11725 Deposition: 14/09/2020
Map released: 25/11/2020
Last modified: 01/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-11725

Transcription termination complex IVa

EMD-11725

Single-particle
4.2 Å
EMD-11725 Deposition: 14/09/2020
Map released: 25/11/2020
Last modified: 01/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Escherichia coli, synthetic construct
Sample: Transcription termination complex IVa
Fitted models: 7ade (Avg. Q-score: 0.235)

Deposition Authors: Said N , Hilal T , Loll B , Wahl CM, Loll B , Wahl MC
Steps toward translocation-independent RNA polymerase inactivation by terminator ATPase rho.
PUBMED: 33243850
DOI: doi:10.1126/science.abd1673
ISSN: 1095-9203
ASTM: SCIEAS
Abstract:
Factor-dependent transcription termination mechanisms are poorly understood. We determined a series of cryo-electron microscopy structures portraying the hexameric adenosine triphosphatase (ATPase) ρ on a pathway to terminating NusA/NusG-modified elongation complexes. An open ρ ring contacts NusA, NusG, and multiple regions of RNA polymerase, trapping and locally unwinding proximal upstream DNA. NusA wedges into the ρ ring, initially sequestering RNA. Upon deflection of distal upstream DNA over the RNA polymerase zinc-binding domain, NusA rotates underneath one capping ρ subunit, which subsequently captures RNA. After detachment of NusG and clamp opening, RNA polymerase loses its grip on the RNA:DNA hybrid and is inactivated. Our structural and functional analyses suggest that ρ, and other termination factors across life, may use analogous strategies to allosterically trap transcription complexes in a moribund state.