Reversal of the DNA-Binding-Induced Loop L1 Conformational Switch in an Engineered Human p53 Protein

Article Article scientifique Article Reversal of the DNA-Binding-Induced Loop L1 Conformational Switch in an Engineered Human p53 Protein eng 2014-02 author Emamzadah Soheila author Tropia Laurence 116996 Département de biologie moléculaire et cellulaire (MOCEL) author Vincenti Ilena 692782 author Falquet Benoît 700035 author Halazonetis Thanos 641033 Département de biologie moléculaire et cellulaire (MOCEL) 936-944 10.1016/j.jmb.2013.12.020 24374182 0022-2836 https://linkinghub.elsevier.com/retrieve/pii/S0022283613008073 <p>The gene encoding the p53 tumor suppressor protein, a sequence-specific DNA binding transcription factor, is the most frequently mutated gene in human cancer. Crystal structures of homo-oligomerizing p53 polypeptides with specific DNA suggest that DNA binding is associated with a conformational switch. Specifically, in the absence of DNA, loop L1 of the p53 DNA binding domain adopts an extended conformation, whereas two p53 subunits switch to a recessed loop L1 conformation when bound to DNA as a tetramer. We previously designed a p53 protein, p53FG, with amino substitutions S121F and V122G targeting loop L1. These two substitutions enhanced the affinity of p53 for specific DNA yet, counterintuitively, decreased the residency time of p53 on DNA. Here, we confirmed these DNA binding properties of p53FG using a different method. We also determined by crystallography the structure of p53FG in its free state and bound to DNA as a tetramer. In the free state, loop L1 adopted a recessed conformation, whereas upon DNA binding, two subunits switched to the extended loop L1 conformation, resulting in a final structure that was very similar to that of wild-type p53 bound to DNA. Thus, altering the apo structure of p53 changed its DNA binding properties, even though the DNA-bound structure was not altered.</p> DNA binding RU SPR conformational selection crystallography induced fit p53 response unit surface plasmon resonance Dewey 540 Dewey 570 43 Département de biologie moléculaire 161 39 Département de biochimie 144 false Journal of Molecular Biology 426 4 bde610d5-4331-4b71-b2f6-734e278c9de8 Article (Published version) Public HALAZONETIS12.pdf 1114256 application/pdf CC BY-NC-ND-3.0 668de95175e16a4b025b5966713fe5eff8e7a6e2293d014ed713c79f3f7cdfc8 openAccess Faculté des sciences / Section de biologie / Département de biologie moléculaire Faculté des sciences / Section de chimie et biochimie / Département de biochimie

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Reversal of the DNA-Binding-Induced Loop L1 Conformational Switch in an Engineered Human p53 Protein	Journal of Molecular Biology			2014	28	10

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Falquet, Benoît