Abstract
A combination of crystallography, biochemistry, and gene expression analysis identifies the coactivator subcomplex Med8C/18/20 as a functionally distinct submodule of the Mediator head module. Med8C forms a conserved alpha-helix that tethers Med18/20 to the Mediator. Deletion of Med8C in vivo results in dissociation of Med18/20 from Mediator and in loss of transcription activity of extracts. Deletion of med8C, med18, or med20 causes similar changes in the yeast transcriptome, establishing Med8C/18/20 as a predominantly positive, gene-specific submodule required for low transcription levels of nonactivated genes, including conjugation genes. The presented structure-based system perturbation is superior to gene deletion analysis of gene regulation.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Electrophoresis, Polyacrylamide Gel
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Gene Deletion*
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Gene Expression Profiling
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Gene Expression Regulation, Fungal
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Mass Spectrometry
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Mediator Complex
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Models, Biological
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Models, Molecular
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Protein Structure, Tertiary
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae Proteins / chemistry*
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Saccharomyces cerevisiae Proteins / genetics*
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Saccharomyces cerevisiae Proteins / metabolism
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Structure-Activity Relationship
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Transcription Factors / chemistry*
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Transcription Factors / genetics*
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Transcription Factors / metabolism
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Transcription, Genetic
Substances
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MED8 protein, S cerevisiae
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Mediator Complex
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Saccharomyces cerevisiae Proteins
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Transcription Factors