1PRR: NMR-DERIVED THREE-DIMENSIONAL SOLUTION STRUCTURE OF PROTEIN S COMPLEXED WITH CALCIUM

Citation:
Abstract
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.
PDB ID: 1PRRDownload
MMDB ID: 57166
PDB Deposition Date: 1994/3/25
Updated in MMDB: 2007/10
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Molecular Components in 1PRR
Label Count Molecule
Protein (1 molecule)
1
Development-specific Protein S
Molecule annotation
Chemicals (2 molecules)
1
2
* Click molecule labels to explore molecular sequence information.

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