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bioRxiv · 10.1101/353136

Structural rearrangement of TFIIS- and TFIIF/TFIIE-like subunits in RNA polymerase I transcription complexes

Tafur, L.·Sadian, Y.·Wetzel, R.·Weis, F.·Muller, C. W.
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Abstract

RNA polymerase (Pol) I is a 14-subunit enzyme that solely transcribes pre-ribosomal RNA. Cryo-EM structures of Pol I initiation and elongation complexes have given first insights into the molecular mechanisms of Pol I transcription. Here, we present cryo-electron microscopy structures of yeast Pol I elongation complexes (ECs) bound to the nucleotide analog GMPCPP at 3.2 to 3.4 [A] resolution that provide additional insight into the functional interplay between the TFIIE/TFIIF-like A49-A34.5 heterodimer and the TFIIS-like subunit A12.2 present in Pol I. Strikingly, most of the nucleotide-bound ECs lack the A49-A34.5 heterodimer and adopt a Pol II-like conformation, in which the A12.2 C-terminal domain is bound in a previously unobserved position at the A135 surface. Our work suggests a regulatory mechanism of Pol I transcription where the association of the A49-A34.5 heterodimer to Pol I is regulated by subunit A12.2, thereby explaining in vitro biochemical and kinetic data.

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Tafur, L., Sadian, Y., Wetzel, R., Weis, F., Muller, C. W.. 2018-07-03. Structural rearrangement of TFIIS- and TFIIF/TFIIE-like subunits in RNA polymerase I transcription complexes. https://doi.org/10.1101/353136

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