Download MendeleyCrystal Structure of a Transcribing RNA Polymerase II Complex Reveals a Complete Transcription Bubble.
Barnes, C.O., Calero, M., Malik, I., Graham, B.W., Spahr, H., Lin, G., Cohen, A.E., Brown, I.S., Zhang, Q., Pullara, F., Trakselis, M.A., Kaplan, C.D., Calero, G.(2015) Mol Cell 59: 258-269
- PubMed: 26186291
- DOI: https://doi.org/10.1016/j.molcel.2015.06.034
- Primary Citation of Related Structures:
5C3E, 5C44, 5C4A, 5C4J, 5C4X - PubMed Abstract:
Notwithstanding numerous published structures of RNA Polymerase II (Pol II), structural details of Pol II engaging a complete nucleic acid scaffold have been lacking. Here, we report the structures of TFIIF-stabilized transcribing Pol II complexes, revealing the upstream duplex and full transcription bubble. The upstream duplex lies over a wedge-shaped loop from Rpb2 that engages its minor groove, providing part of the structural framework for DNA tracking during elongation. At the upstream transcription bubble fork, rudder and fork loop 1 residues spatially coordinate strand annealing and the nascent RNA transcript. At the downstream fork, a network of Pol II interactions with the non-template strand forms a rigid domain with the trigger loop (TL), allowing visualization of its open state. Overall, our observations suggest that "open/closed" conformational transitions of the TL may be linked to interactions with the non-template strand, possibly in a synchronized ratcheting manner conducive to polymerase translocation.
Organizational Affiliation:
Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
