Mechanism of ATP-dependent promoter melting by transcription factor IIH.
We show that transcription factor IIH ERCC3 subunit, the DNA helicase responsible for adenosine triphosphate (ATP)-dependent promoter melting during transcription initiation, does not interact with the promoter region that undergoes melting but instead interacts with DNA downstream of this region. We show further that promoter melting does not change protein-DNA interactions upstream of the region that undergoes melting but does change interactions within and downstream of this region. Our results rule out the proposal that IIH functions in promoter melting through a conventional DNA-helicase mechanism. We propose that IIH functions as a molecular wrench: rotating downstream DNA relative to fixed upstream protein-DNA interactions, thereby generating torque on, and melting, the intervening DNA.
Kim
T K
TK
Howard Hughes Medical Institute, Division of Nucleic Acids Enzymology, Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
Ebright
R H
RH
Reinberg
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D
D000255:Adenosine Triphosphate / Q000378:metabolism*; D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012319:RNA Polymerase II / Q000378:metabolism; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C066644:transcription factor TFIIE; C072022:XPBC-ERCC-3 protein; D051758:Transcription Factor TFIIH; D000255:Adenosine Triphosphate; D004247:DNA; D012319:RNA Polymerase II; D004265:DNA Helicases