Structure of the tau60/Delta tau91 subcomplex of yeast transcription factor IIIC: insights into preinitiation complex assembly

Mol Cell. 2006 Oct 20;24(2):221-32. doi: 10.1016/j.molcel.2006.08.013.

Abstract

Yeast RNA polymerase III is recruited upon binding of subcomplexes tauA and tauB of transcription factor IIIC (TFIIIC) to the A and B blocks of tRNA gene promoters. The tauB subcomplex consists of subunits tau60, tau91, and tau138. We determined the 3.2 A crystal structure of tau60 bound to a large C-terminal fragment of tau91 (Deltatau91). Deltatau91 protein contains a seven-bladed propeller preceded by an N-terminal extension, whereas tau60 contains a structurally homologous propeller followed by a C-terminal domain with a novel alpha/beta fold. The two propeller domains do not have any detectable DNA binding activity and mediate heterodimer formation that may serve as scaffold for tau138 assembly. We show that the C-terminal tau60 domain interacts with the TATA binding protein (TBP). Recombinant tauB recruits TBP and stimulates TFIIIB-directed transcription on a TATA box containing tRNA gene, implying a combined contribution of tauA and tauB to preinitiation complex formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Crystallography, X-Ray
  • Dimerization
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Binding
  • Protein Conformation
  • Protein Folding
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Transcription Factors, TFIII / chemistry*
  • Transcription Factors, TFIII / physiology*
  • Transcription, Genetic

Substances

  • Recombinant Proteins
  • Transcription Factors, TFIII
  • transcription factor TFIIIC

Associated data

  • PDB/2J04
  • PDB/R2J04SF