title: Regulation of DNA binding of p53 by its C-terminal domain.
abstract: The tumor suppressor p53 is a tetrameric multi-domain transcription factor. Its C-terminal domain is thought to regulate the binding of its core domain to specific recognition sequences in promoters. The mechanism of regulation by the C-terminal domain and the role of its post-translational modification are controversial. We have examined the binding of DNA in solution to a series of unmodified p53 constructs that lack various domains. The specific DNA sequences bind tightly to the core domain, irrespective of whether or not the C-terminal domain is part of the construct. Unmodified p53 is accordingly an active DNA binding protein. Non-specific DNA sequences do not inhibit directly the binding of the specific sequences to the core but bind to the C terminus and inhibit p53 via that binding mode. Using NMR, we identified the residues of the C terminus that interact with the non-specific DNA. They include residues that are known to be modified post-translationally. Our data provide direct support for the regulatory role of the C terminus in the activity of p53 and show that p53 containing the unmodified C terminus actively binds to short double-stranded DNA.
authors.affiliation: Cambridge University Chemical Laboratory and Cambridge Centre for Protein Engineering, Medical Research Council Centre, Hills Road, Cambridge CB2 2QH, UK.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Weinberg
authors.forename: Stefan M V
authors.initials: SM
authors.lastname: Freund
authors.forename: Dmitry B
authors.initials: DB
authors.lastname: Veprintsev
authors.forename: Mark
authors.initials: M
authors.lastname: Bycroft
authors.forename: Alan R
authors.initials: AR
authors.lastname: Fersht
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D005454:Fluorescence Polarization; D006801:Humans; D066298:In Vitro Techniques; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000235:genetics; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051736:Proto-Oncogene Proteins c-mdm2; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D004247:DNA; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2