Core promoter-dependent TFIIB conformation and a role for TFIIB conformation in transcription start site selection.
The general transcription factor TFIIB plays a central role in the selection of the transcription initiation site. The mechanisms involved are not clear, however. In this study, we analyze core promoter features that are responsible for the susceptibility to mutations in TFIIB and cause a shift in the transcription start site. We show that TFIIB can modulate both the 5' and 3' parameters of transcription start site selection in a manner dependent upon the sequence of the initiator. Mutations in TFIIB that cause aberrant transcription start site selection concentrate in a region that plays a pivotal role in modulating TFIIB conformation. Using epitope-specific antibody probes, we show that a TFIIB mutant that causes aberrant transcription start site selection assembles at the promoter in a conformation different from that for wild-type TFIIB. In addition, we uncover a core promoter-dependent effect on TFIIB conformation and provide evidence for novel sequence-specific TFIIB promoter contacts.
Fairley
Jennifer A
JA
School of Biological Sciences, University of Manchester, United Kingdom.
Evans
Rachel
R
Hawkes
Nicola A
NA
Roberts
Stefan G E
SG
D024509:3' Flanking Region / Q000502:physiology; D024506:5' Flanking Region / Q000502:physiology; D001483:Base Sequence; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000502:physiology*; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D035581:Transcription Factor TFIIB; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D024363:Transcription Initiation Site / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*
D046911:Macromolecular Substances; D035581:Transcription Factor TFIIB; D014157:Transcription Factors