EMD-11842
Schizosaccharomyces pombe RNA polymerase I (elongation complex)
EMD-11842
Single-particle3.9 Å
Deposition: 14/10/2020
Map released: 24/02/2021
Last modified: 09/10/2024
Sample Organism:
Schizosaccharomyces pombe (strain 972 / ATCC 24843),
synthetic construct
Sample: S. pombe RNA polymerase I - elongation complex
Fitted models: 7aoe (Avg. Q-score: 0.422)
Deposition Authors: Heiss F, Daiss J
Sample: S. pombe RNA polymerase I - elongation complex
Fitted models: 7aoe (Avg. Q-score: 0.422)
Deposition Authors: Heiss F, Daiss J
Conserved strategies of RNA polymerase I hibernation and activation.
Abstract:
RNA polymerase (Pol) I transcribes the ribosomal RNA precursor in all eukaryotes. The mechanisms 'activation by cleft contraction' and 'hibernation by dimerization' are unique to the regulation of this enzyme, but structure-function analysis is limited to baker's yeast. To understand whether regulation by such strategies is specific to this model organism or conserved among species, we solve three cryo-EM structures of Pol I from Schizosaccharomyces pombe in different functional states. Comparative analysis of structural models derived from high-resolution reconstructions shows that activation is accomplished by a conserved contraction of the active center cleft. In contrast to current beliefs, we find that dimerization of the S. pombe polymerase is also possible. This dimerization is achieved independent of the 'connector' domain but relies on two previously undescribed interfaces. Our analyses highlight the divergent nature of Pol I transcription systems from their counterparts and suggest conservation of regulatory mechanisms among organisms.
RNA polymerase (Pol) I transcribes the ribosomal RNA precursor in all eukaryotes. The mechanisms 'activation by cleft contraction' and 'hibernation by dimerization' are unique to the regulation of this enzyme, but structure-function analysis is limited to baker's yeast. To understand whether regulation by such strategies is specific to this model organism or conserved among species, we solve three cryo-EM structures of Pol I from Schizosaccharomyces pombe in different functional states. Comparative analysis of structural models derived from high-resolution reconstructions shows that activation is accomplished by a conserved contraction of the active center cleft. In contrast to current beliefs, we find that dimerization of the S. pombe polymerase is also possible. This dimerization is achieved independent of the 'connector' domain but relies on two previously undescribed interfaces. Our analyses highlight the divergent nature of Pol I transcription systems from their counterparts and suggest conservation of regulatory mechanisms among organisms.