Summary information and primary citation

PDB-id
6ruo; SNAP-derived features in text and JSON formats; DNAproDB
Class
transcription
Method
cryo-EM (3.5 Å)
Summary
RNA polymerase i open complex conformation 1
Reference
Sadian Y, Baudin F, Tafur L, Murciano B, Wetzel R, Weis F, Muller CW (2019): "Molecular insight into RNA polymerase I promoter recognition and promoter melting." Nat Commun, 10, 5543. doi: 10.1038/s41467-019-13510-w.
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.

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