Year: 2018
Type: article
Abstract: RNA polymerase III (Pol III) transcription initiation requires the action of the transcription factor IIIB (TFIIIB) and is highly regulated. Here, we determine the structures of Pol III pre-initiation complexes (PICs) using single particle cryo-electron microscopy (cryo-EM). We observe stable Pol III-TFIIIB complexes using nucleic acid scaffolds mimicking various functional states, in which TFIIIB tightly encircles the upstream promoter DNA. There is an intricate interaction between TFIIIB and Pol III, which stabilizes the winged-helix domains of the C34 subunit of Pol III over the active site cleft. The architecture of Pol III PIC more resembles that of the Pol II PIC than the Pol I PIC. In addition, we also obtain a 3D reconstruction of Pol III in complex with TFIIIB using the elongation complex (EC) scaffold, shedding light on the mechanism of facilitated recycling of Pol III prior to transcription re-initiation.
Source: Cell Discovery
Institutions: Northwestern University, Georgia State University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,590
Funders: National Science Foundation, U.S. Department of Energy, U.S. Department of Health and Human Services, American Cancer Society, Chicago Community Trust, Northwestern University, Chicago Biomedical Consortium, National Energy Research Scientific Computing Center, National Institutes of Health, Office of Science, Chemistry of Life Processes Institute, National Institute of General Medical Sciences, Division of Chemistry
Awards: G113847987, G122673668, G1286236842, G13969156, G157102116, G1677143136, G1863003419, G3083819904, G382641700, G419881185, G42916606, G4334059255, G4501827968, G498139845, G5076365615, G5094606986, G509686445, G6037206029, Integrative modeling of PCNA assemblies engaged in genome duplication and repair, G647246560, G6652958823, G969889393
OpenAlex ID: W2851949430