title: The tetramer of p53 in the absence of DNA forms a relaxed quaternary state.
abstract: p53 is a tetrameric multidomain protein that triggers the anticancer cellular response to stress. We have calculated a three-dimensional reconstruction of full-length human p53 in the absence of DNA using single-particle electron microscopy. The reconstruction of DNA-free full-length p53 shows a square-shaped structure with four distinct domains and a hollow center. In comparison with the known compacted DNA-bound full-length p53 structures, the DNA-free p53 tetramer adopts a relaxed conformation with separated monomers and oligomerization interfaces different from those of the DNA-bound conformation.
authors.affiliation: Laboratory of Structural Biochemistry, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0378, La Jolla, CA 92093, USA.
authors.forename: Nam
authors.initials: N
authors.lastname: Pham
authors.forename: Armando
authors.initials: A
authors.lastname: Lucumi
authors.forename: Nikki
authors.initials: N
authors.lastname: Cheung
authors.forename: Hector
authors.initials: H
authors.lastname: Viadiu
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry*
chemical_list: D001704:Biopolymers; D016159:Tumor Suppressor Protein p53; D004247:DNA