Download MendeleyThe cryo-EM structure of a 12-subunit variant of RNA polymerase I reveals dissociation of the A49-A34.5 heterodimer and rearrangement of subunit A12.2.
Tafur, L., Sadian, Y., Hanske, J., Wetzel, R., Weis, F., Muller, C.W.(2019) Elife 8
- PubMed: 30913026
- DOI: https://doi.org/10.7554/eLife.43204
- Primary Citation of Related Structures:
6HKO, 6HLQ, 6HLR, 6HLS - PubMed Abstract:
RNA polymerase (Pol) I is a 14-subunit enzyme that solely transcribes pre-ribosomal RNA. Cryo-electron microscopy (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-EM structures of yeast Pol I elongation complexes (ECs) bound to the nucleotide analog GMPCPP at 3.2 to 3.4 Å resolution that provide additional insight into the functional interplay between the Pol I-specific transcription-like factors A49-A34.5 and A12.2. 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 structural and biochemical data suggest a mechanism where reversible binding of the A49-A34.5 heterodimer could contribute to the regulation of Pol I transcription initiation and elongation.
Organizational Affiliation:
Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
