title: Two p53 tetramers bind one consensus DNA response element.
abstract: p53 tumor suppressor is a transcription factor that controls cell cycle and genetic integrity. In response to genotoxic stress p53 activates DNA repair, cell cycle arrest, apoptosis or senescence, which are initiated via p53 binding to its specific DNA response elements (RE). The consensus p53 DNA RE consists of two decameric palindromic half-site sequences. Crystallographic studies have demonstrated that two isolated p53 DNA-binding core domains interact with one half-site of the p53 DNA REs suggesting that one p53 tetramer is bound to one RE. However, our recent 3D cryo-EM studies showed that the full-length p53 tetramer is bound to only one half-site of RE.Here, we have used biochemical and electron microscopy (EM) methods to analyze DNA-binding of human and murine p53 tetramers to various p53 DNA REs. Our new results demonstrate that two p53 tetramers can interact sequence-specifically with one DNA RE at the same time. In particular, the EM structural analysis revealed that two p53 tetramers bind one DNA RE simultaneously with DNA positioned between them. These results demonstrate a mode different from that assumed previously for the p53-DNA interaction and suggest important biological implications on p53 activity as a transcriptional regulator of cellular response to stress.
authors.affiliation: Institute for Structural and Molecular Biology, School of Biological Sciences, Birkbeck College, London WC1E 7HX, UK Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, UK.
authors.forename: Sinéad
authors.initials: S
authors.lastname: Kearns
authors.affiliation: Max Planck Institute for Molecular Genetics, Ihnestrasse, Berlin 14195, Germany.
authors.forename: Rudi
authors.initials: R
authors.lastname: Lurz
authors.affiliation: Institute for Structural and Molecular Biology, School of Biological Sciences, Birkbeck College, London WC1E 7HX, UK e.orlova@cryst.bbk.ac.uk.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Orlova
authors.affiliation: Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, UK a.okorokov@ucl.ac.uk.
authors.forename: Andrei L
authors.initials: AL
authors.lastname: Okorokov
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002453:Cell Cycle; D004249:DNA Damage / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D055029:Inverted Repeat Sequences / Q000235:genetics; D051379:Mice; D011487:Protein Conformation; D000072417:Protein Domains / Q000235:genetics; D055503:Protein Multimerization / Q000235:genetics; D017434:Protein Structure, Tertiary; D020218:Response Elements / Q000235:genetics*; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53