Structural and functional interactions of transcription factor (TF) IIA with TFIIE and TFIIF in transcription initiation by RNA polymerase II.
A topological model for transcription initiation by RNA polymerase II (RNAPII) has recently been proposed. This model stipulates that wrapping of the promoter DNA around RNAPII and the general initiation factors TBP, TFIIB, TFIIE, TFIIF and TFIIH induces a torsional strain in the DNA double helix that facilitates strand separation and open complex formation. In this report, we show that TFIIA, a factor previously shown to both stimulate basal transcription and have co-activator functions, is located near the cross-point of the DNA loop where it can interact with TBP, TFIIE56, TFIIE34, and the RNAPII-associated protein (RAP) 74. In addition, we demonstrate that TFIIA can stimulate basal transcription by stimulating the functions of both TFIIE34 and RAP74 during the initiation step of the transcription reaction. These results provide novel insights into mechanisms of TFIIA function.
Langelier
M F
MF
Laboratory of Gene Transcription, Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, Québec H2W 1R7, Canada.
Forget
D
D
Rojas
A
A
Porlier
Y
Y
Burton
Z F
ZF
Coulombe
B
B
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D005656:Fungal Proteins / Q000378:metabolism; D017353:Gene Deletion; D006801:Humans; D007700:Kinetics; D008027:Light; D008954:Models, Biological; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000378:metabolism*; D035561:Transcription Factor TFIIA; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic
D005656:Fungal Proteins; D035561:Transcription Factor TFIIA; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C066644:transcription factor TFIIE; D012319:RNA Polymerase II; C056604:transcription factor TFIIF