Abstract
The X-ray structure of a ternary complex of Negative Cofactor 2 (NC2), the TATA box binding protein (TBP), and DNA has been determined at 2.6 A resolution. The N termini of NC2 alpha and beta resemble histones H2A and H2B, respectively, and form a heterodimer that binds to the bent DNA double helix on the underside of the preformed TBP-DNA complex via electrostatic interactions. NC2beta contributes to inhibition of TATA-dependent transcription through interactions of its C-terminal alpha helix with a conserved hydrophobic feature on the upper surface of TBP, which in turn positions the penultimate alpha helix of NC2beta to block recognition of the TBP-DNA complex by transcription factor IIB. Further regulatory implications of the NC2 heterodimer structure are discussed.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Caenorhabditis elegans
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Crystallography, X-Ray / methods
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DNA / chemistry*
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DNA / metabolism
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DNA-Binding Proteins / chemistry*
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DNA-Binding Proteins / metabolism
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Drosophila melanogaster
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Histones / chemistry
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Humans
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Models, Molecular
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Molecular Sequence Data
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Nucleic Acid Conformation
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Phosphoproteins / chemistry*
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Phosphoproteins / metabolism
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Protein Structure, Secondary
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Sequence Alignment
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Sequence Homology, Amino Acid
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Static Electricity
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TATA Box*
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TATA-Box Binding Protein
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Transcription Factor TFIIA
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Transcription Factor TFIIB
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Transcription Factors / chemistry*
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Transcription Factors / metabolism
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Transcription, Genetic
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Xenopus laevis
Substances
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DNA-Binding Proteins
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Histones
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Phosphoproteins
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TATA-Box Binding Protein
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Transcription Factor TFIIA
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Transcription Factor TFIIB
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Transcription Factors
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down-regulator of transcription 1
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DNA