2vtx

ACTIVATION OF NUCLEOPLASMIN, AN OLIGOMERIC HISTONE CHAPERONE, CHALLENGES ITS STABILITY

spinqualitylabelsall models 2vtx, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vtx is a 10 chain structure with sequence from Xenopus laevis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Nucleoplasmin (NP) is a pentameric, ring-shaped histone chaperone involved in chromatin remodeling processes such as sperm decondensation at fertilization. Monomers are formed by a core domain, responsible for oligomerization, that confers the protein a high stability and compactness and a flexible tail domain, that harbors a polyglutamic tract and the nuclear localization signal. Fully activated NP presents multiple phosphorylated residues in the tail and in flexible regions of the core domain. In this work, we analyze the effect of activation on the structure and stability of the full-length protein and the isolated core domain through phosphorylation mimicking mutations. We have solved the crystal structure of an activated NP core domain that, however, is not significantly different from that of the wild-type, inactive, NP core. Nevertheless, we find that NP activation results in a strong destabilization of the pentamer probably due to electrostatic repulsion. Moreover, characterization of the hydrodynamic properties of both full-length and core domain proteins indicates that activating mutations lead to an expansion of the NP pentamer in solution. These findings suggest that NP needs a compact and stable structure to afford the accumulation of negative charges that weakens its quaternary interactions but is required for its biological function. Activation of Nucleoplasmin, an Oligomeric Histone Chaperone, Challenges Its Stability (dagger) (,) (double dagger).,Taneva SG, Munoz IG, Franco G, Falces J, Arregi I, Muga A, Montoya G, Urbaneja MA, Banuelos S Biochemistry. 2008 Dec 4. PMID:19055325 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Nucleoplasmin

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