Summary information and primary citation
- PDB-id
- 8ffz; SNAP-derived features in text and JSON formats;
DNAproDB
- Class
- transcription-DNA
- Method
- cryo-EM (3.8 Å)
- Summary
- Tfiiia-tfiiic-brf1-tbp complex bound to 5s rrna gene
- Reference
- Talyzina A, Han Y, Banerjee C, Fishbain S, Reyes A, Vafabakhsh R, He Y (2023): "Structural basis of TFIIIC-dependent RNA polymerase III transcription initiation." Mol.Cell, 83, 2641. doi: 10.1016/j.molcel.2023.06.015.
- Abstract
- RNA polymerase III (Pol III) is responsible for transcribing 5S ribosomal RNA (5S rRNA), tRNAs, and other short non-coding RNAs. Its recruitment to the 5S rRNA promoter requires transcription factors TFIIIA, TFIIIC, and TFIIIB. Here, we use cryoelectron microscopy (cryo-EM) to visualize the S. cerevisiae complex of TFIIIA and TFIIIC bound to the promoter. Gene-specific factor TFIIIA interacts with DNA and acts as an adaptor for TFIIIC-promoter interactions. We also visualize DNA binding of TFIIIB subunits, Brf1 and TBP (TATA-box binding protein), which results in the full-length 5S rRNA gene wrapping around the complex. Our smFRET study reveals that the DNA within the complex undergoes both sharp bending and partial dissociation on a slow timescale, consistent with the model predicted from our cryo-EM results. Our findings provide new insights into the transcription initiation complex assembly on the 5S rRNA promoter and allow us to directly compare Pol III and Pol II transcription adaptations.
