title: Characterization of the p300 Taz2-p53 TAD2 complex and comparison with the p300 Taz2-p53 TAD1 complex.
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.
authors.affiliation: †Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Miller Jenkins
authors.affiliation: ‡Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Hanqiao
authors.initials: H
authors.lastname: Feng
authors.affiliation: †Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Stewart R
authors.initials: SR
authors.lastname: Durell
authors.affiliation: †Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Harichandra D
authors.initials: HD
authors.lastname: Tagad
authors.affiliation: †Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Sharlyn J
authors.initials: SJ
authors.lastname: Mazur
authors.affiliation: §Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, Maryland 21702, United States.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Tropea
authors.affiliation: ‡Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Yawen
authors.initials: Y
authors.lastname: Bai
authors.affiliation: †Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors.forename: Ettore
authors.initials: E
authors.lastname: Appella
mesh_terms: D019943:Amino Acid Substitution; D002152:Calorimetry, Differential Scanning; D050881:E1A-Associated p300 Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051548:Histone Acetyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D050505:Mutant Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; D051548:Histone Acetyltransferases