Tfb6, a previously unidentified subunit of the general transcription factor TFIIH, facilitates dissociation of Ssl2 helicase after transcription initiation

Proc Natl Acad Sci U S A. 2012 Mar 27;109(13):4816-21. doi: 10.1073/pnas.1201448109. Epub 2012 Mar 12.

Abstract

General transcription factor TFIIH, previously described as a 10-subunit complex, is essential for transcription and DNA repair. An eleventh subunit now identified, termed Tfb6, exhibits 45% sequence similarity to human nuclear mRNA export factor 5. Tfb6 dissociates from TFIIH as a heterodimer with the Ssl2 subunit, a DNA helicase that drives promoter melting for the initiation of transcription. Tfb6 does not, however, dissociate Ssl2 from TFIIH in the context of a fully assembled transcription preinitiation complex. Our findings suggest a dynamic state of Ssl2, allowing its engagement in multiple cellular processes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, Liquid
  • DNA Helicases / metabolism*
  • Gene Deletion
  • Gene Expression Regulation, Fungal / radiation effects
  • Humans
  • Mass Spectrometry
  • Phenotype
  • Phosphorylation / radiation effects
  • Protein Binding / radiation effects
  • Protein Subunits / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / radiation effects
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Temperature
  • Transcription Factor TFIIH / chemistry
  • Transcription Factor TFIIH / metabolism*
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism*
  • Transcription, Genetic* / radiation effects
  • Ultraviolet Rays

Substances

  • Protein Subunits
  • RNA, Messenger
  • SSL2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Tfb6 protein, S cerevisiae
  • Transcription Factors
  • Transcription Factor TFIIH
  • DNA Helicases