EMD-10020
RNA Polymerase I Open Complex conformation 2 focused refinement on Pol
EMD-10020
Single-particle2.96 Å
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Map released: 22/04/2020
Last modified: 22/04/2020
Sample Organism:
Saccharomyces cerevisiae,
synthetic construct
Sample: RNA Polymerase I Open Complex conformation 2 focused refinement on Pol
Deposition Authors: Mueller CW, Sadian Y
Sample: RNA Polymerase I Open Complex conformation 2 focused refinement on Pol
Deposition Authors: Mueller CW, Sadian Y
Molecular insight into RNA polymerase I promoter recognition and promoter melting.
Sadian Y,
Baudin F
,
Tafur L
,
Murciano B
,
Wetzel R,
Weis F
,
Muller CW
(2019) Nat Commun , 10 , 5543 - 5543
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(2019) Nat Commun , 10 , 5543 - 5543
Abstract:
RNA polymerase I (Pol I) assembles with core factor (CF) and Rrn3 on the rDNA core promoter for transcription initiation. Here, we report cryo-EM structures of closed, intermediate and open Pol I initiation complexes from 2.7 to 3.7 Å resolution to visualize Pol I promoter melting and to structurally and biochemically characterize the recognition mechanism of Pol I promoter DNA. In the closed complex, double-stranded DNA runs outside the DNA-binding cleft. Rotation of CF and upstream DNA with respect to Pol I and Rrn3 results in the spontaneous loading and opening of the promoter followed by cleft closure and positioning of the Pol I A49 tandem winged helix domain (tWH) onto DNA. Conformational rearrangement of A49 tWH leads to a clash with Rrn3 to initiate complex disassembly and promoter escape. Comprehensive insight into the Pol I transcription initiation cycle allows comparisons with promoter opening by Pol II and Pol III.
RNA polymerase I (Pol I) assembles with core factor (CF) and Rrn3 on the rDNA core promoter for transcription initiation. Here, we report cryo-EM structures of closed, intermediate and open Pol I initiation complexes from 2.7 to 3.7 Å resolution to visualize Pol I promoter melting and to structurally and biochemically characterize the recognition mechanism of Pol I promoter DNA. In the closed complex, double-stranded DNA runs outside the DNA-binding cleft. Rotation of CF and upstream DNA with respect to Pol I and Rrn3 results in the spontaneous loading and opening of the promoter followed by cleft closure and positioning of the Pol I A49 tandem winged helix domain (tWH) onto DNA. Conformational rearrangement of A49 tWH leads to a clash with Rrn3 to initiate complex disassembly and promoter escape. Comprehensive insight into the Pol I transcription initiation cycle allows comparisons with promoter opening by Pol II and Pol III.