1j55
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The Crystal Structure of Ca+-bound Human S100P Determined at 2.0A Resolution by X-ray
OverviewOverview
S100P is a small calcium-binding protein of the S100 EF-hand-containing, family of proteins. Elevated levels of its mRNA are reported to be, associated with the progression to hormone independence and metastasis of, prostate cancer and to be associated with loss of senescence in human, breast epithelial cells in vitro. The first structure of human recombinant, S100P in calcium-bound form is now reported at 2.0A resolution by X-ray, diffraction. A flexible linker connects the two EF-hand motifs. The, protein exists as a homodimer formed by non-covalent interactions between, large hydrophobic areas on monomeric S100P. Experiments with an optical, biosensor to study binding parameters of the S100P monomer interaction, showed that the association rate constant was faster in the presence of, calcium than in their absence, whereas the dissociation rate constant was, independent of calcium. The K(d) values were 64(+/-24)nM and 2.5(+/-0.8), microM in the presence and in the absence of calcium ions, respectively., Dimerization of S100P is demonstrated in vivo using the yeast two-hybrid, system. The effect of mutation of specific amino acids suggests that, dimerization in vivo can be affected by amino acids on the dimer interface, and in the hydrophobic core.
About this StructureAbout this Structure
1J55 is a Single protein structure of sequence from Homo sapiens with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
The crystal structure at 2A resolution of the Ca2+ -binding protein S100P., Zhang H, Wang G, Ding Y, Wang Z, Barraclough R, Rudland PS, Fernig DG, Rao Z, J Mol Biol. 2003 Jan 24;325(4):785-94. PMID:12507480
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