Summary information and primary citation
- PDB-id
-
6cnc;
DSSR-derived features in text and
JSON formats
- Class
- transcription-DNA
- Method
- cryo-EM (4.1 Å)
- Summary
- Yeast RNA polymerase iii open complex
- Reference
-
Han Y, Yan C, Fishbain S, Ivanov I, He Y (2018):
"Structural
visualization of RNA polymerase III transcription
machineries." Cell Discov,
4, 40. doi: 10.1038/s41421-018-0044-z.
- 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.
