Structural mechanism of ATP-independent transcription initiation by RNA polymerase I.Han, Y., Yan, C., Nguyen, T.H.D., Jackobel, A.J., Ivanov, I., Knutson, B.A., He, Y.
(2017) Elife 6: --
- PubMed: 28623663
- DOI: 10.7554/eLife.27414
- Primary Citation of Related Structures:
- PubMed Abstract:
Transcription initiation by RNA Polymerase I (Pol I) depends on the Core Factor (CF) complex to recognize the upstream promoter and assemble into a Pre-Initiation Complex (PIC). Here, we solve a structure of <i>Saccharomyces cerevisiae </i> Pol I-CF ...
Transcription initiation by RNA Polymerase I (Pol I) depends on the Core Factor (CF) complex to recognize the upstream promoter and assemble into a Pre-Initiation Complex (PIC). Here, we solve a structure of Saccharomyces cerevisiae Pol I-CF-DNA to 3.8 Å resolution using single-particle cryo-electron microscopy. The structure reveals a bipartite architecture of Core Factor and its recognition of the promoter from -27 to -16. Core Factor's intrinsic mobility correlates well with different conformational states of the Pol I cleft, in addition to the stabilization of either Rrn7 N-terminal domain near Pol I wall or the tandem winged helix domain of A49 at a partially overlapping location. Comparison of the three states in this study with the Pol II system suggests that a ratchet motion of the Core Factor-DNA sub-complex at upstream facilitates promoter melting in an ATP-independent manner, distinct from a DNA translocase actively threading the downstream DNA in the Pol II PIC.
Department of Molecular Biosciences, Northwestern University, Evanston, United States.,Department of Chemistry, Georgia State University, Atlanta, United States.,Howard Hughes Medical Institute, University of California, Berkeley, United States.,Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, United States.,Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, United States.