Abstract
The p53 tumor suppressor is a critical mediator of the cellular response to stress. The N-terminal transactivation domain of p53 makes protein interactions that promote its function as a transcription factor. Among those cofactors is the histone acetyltransferase p300, which both stabilizes p53 and promotes local chromatin unwinding. Here, we report the nuclear magnetic resonance solution structure of the Taz2 domain of p300 bound to the second transactivation subdomain of p53. In the complex, p53 forms an α-helix between residues 47 and 55 that interacts with the α1-α2-α3 face of Taz2. Mutational analysis indicated several residues in both p53 and Taz2 that are critical for stabilizing the interaction. Finally, further characterization of the complex by isothermal titration calorimetry revealed that complex formation is pH-dependent and releases a bound chloride ion. This study highlights differences in the structures of complexes formed by the two transactivation subdomains of p53 that may be broadly observed and play critical roles in p53 transcriptional activity.
Publication types
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Comparative Study
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Research Support, N.I.H., Intramural
MeSH terms
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Amino Acid Substitution
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Calorimetry, Differential Scanning
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E1A-Associated p300 Protein / chemistry
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E1A-Associated p300 Protein / genetics
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E1A-Associated p300 Protein / metabolism*
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Histone Acetyltransferases / chemistry
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Histone Acetyltransferases / genetics
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Histone Acetyltransferases / metabolism*
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Humans
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Hydrogen Bonding
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Hydrogen-Ion Concentration
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Kinetics
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Models, Molecular*
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Molecular Dynamics Simulation
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Mutagenesis, Site-Directed
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Mutant Proteins / chemistry
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Mutant Proteins / metabolism
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Nuclear Magnetic Resonance, Biomolecular
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Peptide Fragments / chemistry
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Peptide Fragments / genetics
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Peptide Fragments / metabolism
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Protein Conformation
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Protein Interaction Domains and Motifs
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Protein Stability
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Protein Structure, Quaternary
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Recombinant Proteins / chemistry
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Recombinant Proteins / metabolism
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Tumor Suppressor Protein p53 / chemistry
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Tumor Suppressor Protein p53 / genetics
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Tumor Suppressor Protein p53 / metabolism*
Substances
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Mutant Proteins
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Peptide Fragments
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Recombinant Proteins
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TP53 protein, human
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Tumor Suppressor Protein p53
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E1A-Associated p300 Protein
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EP300 protein, human
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Histone Acetyltransferases