title: Structural diversity of calcium binding sites.
abstract: Calcium Binding Proteins (CBPs) play a major role in many biological processes. The three dimensional (3D) structure of several CBPs has been resolved by means of X-ray crystallography and nuclear magnetic resonance. We consulted several databases to compile a collection of CBPs of known 3D structure. The analysis of these data shows, the CBP structures are distributed over many different functional families and fold types. The binding site itself is less frequently formed by a continuous sequence segment. In the majority of the cases Ca(2+) ion coordination is spread over different secondary structure elements with considerable distance on the amino acid sequence. The sidechain of amino acids Asp and Glu are the major interaction partner for the ion. Less frequently it is the side chain of Asn, Gln, Ser and Thr. Often main chain oxygen contributes to the Ca(2+) coordination. In addition, water molecules are frequently involved.
authors.affiliation: Department of Molecular Biology, University of Salzburg, 5020 Salzburg, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bindreither
authors.forename: Peter
authors.initials: P
authors.lastname: Lackner
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000737:chemistry*; D002135:Calcium-Binding Proteins / Q000737:chemistry; D020134:Catalytic Domain; D019295:Computational Biology / Q000379:methods; D018360:Crystallography, X-Ray / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D010738:Type C Phospholipases / Q000737:chemistry
chemical_list: D002135:Calcium-Binding Proteins; D007477:Ions; D010738:Type C Phospholipases; D002118:Calcium