SNAP output for PDB entry 8cli [SNAP web server]

PDB-id

8cli; SNAP-derived features in text and JSON formats; DNAproDB

Class

transcription

Method

cryo-EM (3.2 Å)

Summary

Tfiiic taub-DNA monomer

Reference

Seifert-Davila W, Girbig M, Hauptmann L, Hoffmann T, Eustermann S, Muller CW (2023): "Structural insights into human TFIIIC promoter recognition." Sci Adv, 9, eadh2019. doi: 10.1126/sciadv.adh2019.

Abstract

Transcription factor (TF) IIIC recruits RNA polymerase (Pol) III to most of its target genes. Recognition of intragenic A- and B-box motifs in transfer RNA (tRNA) genes by TFIIIC modules τA and τB is the first critical step for tRNA synthesis but is mechanistically poorly understood. Here, we report cryo-electron microscopy structures of the six-subunit human TFIIIC complex unbound and bound to a tRNA gene. The τB module recognizes the B-box via DNA shape and sequence readout through the assembly of multiple winged-helix domains. TFIIIC220 forms an integral part of both τA and τB connecting the two subcomplexes via a ~550-amino acid residue flexible linker. Our data provide a structural mechanism by which high-affinity B-box recognition anchors TFIIIC to promoter DNA and permits scanning for low-affinity A-boxes and TFIIIB for Pol III activation.