EMD-37411

Single-particle
2.94 Å
EMD-37411 Deposition: 08/09/2023
Map released: 06/12/2023
Last modified: 03/01/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-37411

De novo transcribing complex 17 (TC17), the early elongation complex with Pol II positioned 17nt downstream of TSS

EMD-37411

Single-particle
2.94 Å
EMD-37411 Deposition: 08/09/2023
Map released: 06/12/2023
Last modified: 03/01/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Sus scrofa, synthetic construct, Homo sapiens, Amanita phalloides
Sample: Structure of transcribing complex 17 (TC17), the early elongation complex with Pol II positioned 17nt downstream of TSS
Fitted models: 8wb0 (Avg. Q-score: 0.437)

Deposition Authors: Chen X , Liu W , Wang Q , Wang X , Ren Y , Qu X , Li W , Xu Y
Structural visualization of transcription initiation in action.
Chen X , Liu W , Wang Q , Wang X , Ren Y , Qu X , Li W , Xu Y
(2023) Science , 382 , eadi5120 - eadi5120
PUBMED: 38127763
DOI: doi:10.1126/science.adi5120
ISSN: 1095-9203
ASTM: SCIEAS
Abstract:
Transcription initiation is a complex process, and its mechanism is incompletely understood. We determined the structures of de novo transcribing complexes TC2 to TC17 with RNA polymerase II halted on G-less promoters when nascent RNAs reach 2 to 17 nucleotides in length, respectively. Connecting these structures generated a movie and a working model. As initially synthesized RNA grows, general transcription factors (GTFs) remain bound to the promoter and the transcription bubble expands. Nucleoside triphosphate (NTP)-driven RNA-DNA translocation and template-strand accumulation in a nearly sealed channel may promote the transition from initially transcribing complexes (ITCs) (TC2 to TC9) to early elongation complexes (EECs) (TC10 to TC17). Our study shows dynamic processes of transcription initiation and reveals why ITCs require GTFs and bubble expansion for initial RNA synthesis, whereas EECs need GTF dissociation from the promoter and bubble collapse for promoter escape.