Wrapping of promoter DNA around the RNA polymerase II initiation complex induced by TFIIF.
The formation of the RNA polymerase II (Pol II) initiation complex was analyzed using site-specific protein-DNA photo-cross-linking. We show that the RAP74 subunit of transcription factor (TF) IIF, through its RAP30-binding domain and an adjacent region necessary for the formation of homomeric interactions in vitro, dramatically alters the distribution of RAP30, TFIIE, and Pol II along promoter DNA between positions -40 and +26. This isomerization of the complex, which requires both TFIIF and TFIIE, is accompanied by tight wrapping of the promoter DNA for almost a full turn around Pol II. Addition of TFIIH enhances photo-cross-linking of Pol II to a number of promoter positions, suggesting that TFIIH tightens the DNA wrap around the enzyme. We present a general model to describe transcription initiation.
Departement de biologie, Faculté des sciences, Université de Sherbrooke, Québec, Canada.
F
F
Robert
M
M
Douziech
D
D
Forget
J M
JM
Egly
J
J
Greenblatt
Z F
ZF
Burton
B
B
Coulombe
D000256:Adenoviridae / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D003432:Cross-Linking Reagents; D004279:DNA, Viral / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D019473:Transcription Factors, TFII
D003432:Cross-Linking Reagents; D004279:DNA, Viral; D011994:Recombinant Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D012319:RNA Polymerase II; C056604:transcription factor TFIIF