Chicago Biomedical Consortium with support from the Searle Funds at The Chicago Community Trust
Catalyst Award
米国
National Science Foundation XSEDE program
CHE110042
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM110387
米国
National Energy Research Scientific Computing Center
DE-AC02-05CH11231
米国
引用
ジャーナル: Cell Discov / 年: 2018 タイトル: Structural visualization of RNA polymerase III transcription machineries. 著者: Yan Han / Chunli Yan / Susan Fishbain / Ivaylo Ivanov / Yuan He / 要旨: 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- ...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.