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CRYSTAL STRUCTURE OF RAT ALPHA-PARVALBUMIN AT 1.05 RESOLUTION
Structural highlights
FunctionPRVA_RAT In muscle, parvalbumin is thought to be involved in relaxation after contraction. It binds two calcium ions. 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 PubMedThe crystal structure of rat alpha-parvalbumin has been determined at 1.05 Angstrom resolution, using synchrotron data collected at Advanced Photon Source beamline 19-ID. After refinement with SHELX, employing anisotropic displacement parameters and riding hydrogen atoms, R = 0.132 and R(free) = 0.162. The average coordinate estimated standard deviations are 0.021 Angstrom and 0.038 Angstrom for backbone atoms and side-chain atoms, respectively. Besides providing a more precise view of the alpha-isoform than previously available, these data permit comparison with the 0.91 Angstrom structure determined for pike beta-parvalbumin. Visualization of the anisotropic displacement parameters as thermal ellipsoids yields insight into the atomic motion within the Ca(2+)-binding sites. The asymmetric unit includes three parvalbumin (PV) molecules. Interestingly, the EF site in one displays uncharacteristic flexibility. The ellipsoids for Asp-92 are particularly large and non-spherical, and the shape of the Ca(2+) ellipsoid implies significant vibrational motion perpendicular to the plane defined by the four y and z ligands. The relative dearth of crystal-packing interactions in this site suggests that the heightened flexibility may be the result of diminished intermolecular contacts. The implication is that, by impeding conformational mobility, crystal-packing forces may cause serious overestimation of EF-hand rigidity. The high quality of the data permitted 11 residues to be modeled in alternative side-chain conformations, including the two core residues, Ile-97 and Leu-105. The discrete disorder observed for Ile-97 may have functional ramifications, providing a mechanism for communicating binding status between the CD and EF binding loops and between the PV metal ion-binding domain and the N-terminal AB region. Crystal structure of rat alpha-parvalbumin at 1.05 Angstrom resolution.,Bottoms CA, Schuermann JP, Agah S, Henzl MT, Tanner JJ Protein Sci. 2004 Jul;13(7):1724-34. Epub 2004 May 28. PMID:15169955[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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