1r5u
From Proteopedia
RNA POLYMERASE II TFIIB COMPLEX
Overview
The structure of the general transcription factor IIB (TFIIB) in a complex with RNA polymerase II reveals three features crucial for transcription initiation: an N-terminal zinc ribbon domain of TFIIB that contacts the "dock" domain of the polymerase, near the path of RNA exit from a transcribing enzyme; a "finger" domain of TFIIB that is inserted into the polymerase active center; and a C-terminal domain, whose interaction with both the polymerase and with a TATA box-binding protein (TBP)-promoter DNA complex orients the DNA for unwinding and transcription. TFIIB stabilizes an early initiation complex, containing an incomplete RNA-DNA hybrid region. It may interact with the template strand, which sets the location of the transcription start site, and may interfere with RNA exit, which leads to abortive initiation or promoter escape. The trajectory of promoter DNA determined by the C-terminal domain of TFIIB traverses sites of interaction with TFIIE, TFIIF, and TFIIH, serving to define their roles in the transcription initiation process.
About this Structure
1R5U is a Protein complex structure of sequences from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
Structural basis of transcription: an RNA polymerase II-TFIIB cocrystal at 4.5 Angstroms., Bushnell DA, Westover KD, Davis RE, Kornberg RD, Science. 2004 Feb 13;303(5660):983-8. PMID:14963322 Page seeded by OCA on Sat May 3 07:07:02 2008
