1prr
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NMR-DERIVED THREE-DIMENSIONAL SOLUTION STRUCTURE OF PROTEIN S COMPLEXED WITH CALCIUM
OverviewOverview
BACKGROUND: Protein S is a developmentally-regulated Ca(2+)-binding protein of the soil bacterium Myxococcus xanthus. It functions by forming protective, multilayer spore surface assemblies which may additionally act as a cell-cell adhesive. Protein S is evolutionarily related to vertebrate lens beta gamma-crystallins. RESULTS: The three-dimensional solution structure of Ca(2+)-loaded protein S has been determined using multi-dimensional heteronuclear NMR spectroscopy. (Sixty structures were calculated, from which thirty were selected with a root mean square difference from the mean of 0.38 A for backbone atoms and 1.22 A for all non-hydrogen atoms.) The structure was analyzed and compared in detail with X-ray crystallographic structures of beta gamma-crystallins. The two internally homologous domains of protein S were compared, and hydrophobic cores, domain interfaces, surface ion pairing, amino-aromatic interactions and potential modes of multimerization are discussed. CONCLUSIONS: Structural features of protein S described here help to explain its overall thermostability, as well as the higher stability and Ca2+ affinity of the amino-terminal domain relative to the carboxy-terminal domain. Two potential modes of multimerization are proposed involving cross-linking of protein S molecules through surface Ca(2+)-binding sites and formation of the intramolecular protein S or gamma B-crystallin interdomain interface in an intermolecular content. This structural analysis may also have implications for Ca(2+)-dependent cell-cell interactions mediated by the vertebrate cadherins and Dictyostelium discoideum protein gp24.
About this StructureAbout this Structure
1PRR is a Single protein structure of sequence from Myxococcus xanthus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
NMR-derived three-dimensional solution structure of protein S complexed with calcium., Bagby S, Harvey TS, Eagle SG, Inouye S, Ikura M, Structure. 1994 Feb 15;2(2):107-22. PMID:8081742
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