Abstract
The Escherichia coli catabolite activator protein (CAP) activates transcription at P(lac), P(gal), and other promoters through interactions with the RNA polymerase alpha subunit carboxyl-terminal domain (alphaCTD). We determined the crystal structure of the CAP-alphaCTD-DNA complex at a resolution of 3.1 angstroms. CAP makes direct protein-protein interactions with alphaCTD, and alphaCTD makes direct protein-DNA interactions with the DNA segment adjacent to the DNA site for CAP. There are no large-scale conformational changes in CAP and alphaCTD, and the interface between CAP and alphaCTD is small. These findings are consistent with the proposal that activation involves a simple "recruitment" mechanism.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Crystallography, X-Ray
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Cyclic AMP Receptor Protein / chemistry*
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Cyclic AMP Receptor Protein / metabolism
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Cyclic AMP Receptor Protein / physiology
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DNA / chemistry*
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DNA / metabolism
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DNA-Directed RNA Polymerases / chemistry*
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DNA-Directed RNA Polymerases / metabolism
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DNA-Directed RNA Polymerases / physiology
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Macromolecular Substances
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Models, Molecular
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Nucleic Acid Conformation
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Protein Binding
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Protein Conformation
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Structure-Activity Relationship
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Transcription, Genetic*
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Transcriptional Activation
Substances
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Cyclic AMP Receptor Protein
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Macromolecular Substances
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DNA
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DNA-Directed RNA Polymerases
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RNA polymerase alpha subunit