Abstract
The Brf1 subunit of TFIIIB plays an important role in recruiting the TATA-binding protein (TBP) to the up-stream region of genes transcribed by RNA polymerase III. When TBP is not bound to promoters, it sequesters its DNA binding domain through dimerization. Promoter assembly factors therefore might be required to dissociate TBP into productively binding monomers. Here we show that Saccharomyces cerevisiae Brf1 induces TBP dimers to dissociate. The high affinity TBP binding domain of Brf1 is not sufficient to promote TBP dimer dissociation but in addition requires the TFIIB homology domain of Brf1. A model is proposed to explain how two distinct functional domains of Brf1 work in concert to dissociate TBP into monomers.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alleles
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Cross-Linking Reagents / pharmacology
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Dimerization
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Gene Deletion
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Glutathione Transferase / metabolism
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Humans
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Models, Biological
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Mutation
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Plasmids / metabolism
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Promoter Regions, Genetic
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Protein Binding
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Protein Structure, Tertiary
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RNA Polymerase III / metabolism*
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Recombinant Proteins / chemistry
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Reverse Transcriptase Polymerase Chain Reaction
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae Proteins
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TATA-Binding Protein Associated Factors
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TATA-Box Binding Protein / chemistry*
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Time Factors
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Transcription Factor TFIIIB / chemistry*
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Transcription Factor TFIIIB / metabolism
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Transcription, Genetic
Substances
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BRF1 protein, S cerevisiae
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BRF1 protein, human
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Cross-Linking Reagents
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Recombinant Proteins
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Saccharomyces cerevisiae Proteins
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TATA-Binding Protein Associated Factors
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TATA-Box Binding Protein
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Transcription Factor TFIIIB
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Glutathione Transferase
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RNA Polymerase III