Binding of TFIIB to RNA polymerase II: Mapping the binding site for the TFIIB zinc ribbon domain within the preinitiation complex.
RNA polymerase II (Pol II) is recruited to promoters by interaction with general transcription factors. The zinc ribbon domain of the general factor TFIIB is essential for Pol II recruitment. Site-specific photocrosslinking and directed hydroxyl radical probing were used to map the location of the TFIIB zinc ribbon domain on Pol II within the transcription preinitiation complex (PIC). These results, along with mutational analysis, suggest that in the PIC, the TFIIB ribbon domain interacts with a surface of the Pol II Dock domain where it overlaps the RNA exit point. This surface is best conserved in polymerases that require a TFIIB-like factor. Our results suggest a general mechanism for interaction of TFIIB-like factors and RNA polymerases and a mechanism for the function of the ribbon domain.
Chen
Hung-Ta
HT
Fred Hutchinson Cancer Research Center and Howard Hughes Medical Institute, 1100 Fairview Avenue N., Mail Stop A1-162, Seattle, WA 98109, USA.
Hahn
Steven
S
D000595:Amino Acid Sequence; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004252:DNA Mutational Analysis; D000939:Epitopes; D005656:Fungal Proteins / Q000378:metabolism; D017665:Hydroxyl Radical; D008027:Light; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D035581:Transcription Factor TFIIB / Q000378:metabolism*; D014158:Transcription, Genetic; D015032:Zinc / Q000737:chemistry*
D003432:Cross-Linking Reagents; D000939:Epitopes; D005656:Fungal Proteins; D010455:Peptides; D035581:Transcription Factor TFIIB; D017665:Hydroxyl Radical; D012319:RNA Polymerase II; D015032:Zinc