Abstract
Eukaryotic transcription initiation requires the assembly of general transcription factors into a pre-initiation complex that ensures the accurate loading of RNA polymerase II (Pol II) at the transcription start site. The molecular mechanism and function of this assembly have remained elusive due to lack of structural information. Here we have used an in vitro reconstituted system to study the stepwise assembly of human TBP, TFIIA, TFIIB, Pol II, TFIIF, TFIIE and TFIIH onto promoter DNA using cryo-electron microscopy. Our structural analyses provide pseudo-atomic models at various stages of transcription initiation that illuminate critical molecular interactions, including how TFIIF engages Pol II and promoter DNA to stabilize both the closed pre-initiation complex and the open-promoter complex, and to regulate start-initiation complexes, combined with the localization of the TFIIH helicases XPD and XPB, support a DNA translocation model of XPB and explain its essential role in promoter opening.
Original language | English (US) |
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Pages (from-to) | 481-486 |
Number of pages | 6 |
Journal | Nature |
Volume | 495 |
Issue number | 7442 |
DOIs | |
State | Published - Mar 28 2013 |
Funding
Acknowledgements We thank C. Inouye for providing us with recombinant TFIIF and TFIIE; P. Grob and T. Houweling for electron microscopy and computer support, respectively; T. Goddard for help with Chimera; and members of the Nogales laboratory for technical advice on image processing. We are thankful to J. Kadonaga, J. Goodrich and M. Cianfrocco for their comments on the manuscript. We thank P. Cooper both for biochemical advice and for her comments on the manuscript. This work was funded by NIGMS (GM63072 to E.N.) and by NCI (CA127364 to D.J.T.). E.N. is a Howard Hughes Medical Institute Investigator.
ASJC Scopus subject areas
- General