6fie
From Proteopedia
Crystallographic structure of calcium loaded Calbindin-D28K.
Structural highlights
Function[CALB1_HUMAN] Buffers cytosolic calcium. May stimulate a membrane Ca(2+)-ATPase and a 3',5'-cyclic nucleotide phosphodiesterase. Publication Abstract from PubMedCalbindin-D28K is a widely expressed calcium-buffering cytoplasmic protein that is involved in many physiological processes. It has been shown to interact with other proteins, suggesting a role as a calcium sensor. Many of the targets of calbindin-D28K are of therapeutic interest: for example, inositol monophosphatase, the putative target of lithium therapy in bipolar disorder. Presented here is the first crystal structure of human calbindin-D28K. There are significant deviations in the tertiary structure when compared with the NMR structure of rat calbindin-D28K (PDB entry 2g9b), despite 98% sequence identity. Small-angle X-ray scattering (SAXS) indicates that the crystal structure better predicts the properties of calbindin-D28K in solution compared with the NMR structure. Here, the first direct visualization of the calcium-binding properties of calbindin-D28K is presented. Four of the six EF-hands that make up the secondary structure of the protein contain a calcium-binding site. Two distinct conformations of the N-terminal EF-hand calcium-binding site were identified using long-wavelength calcium single-wavelength anomalous dispersion (SAD). This flexible region has previously been recognized as a protein-protein interaction interface. SAXS data collected in both the presence and absence of calcium indicate that there are no large structural differences in the globular structure of calbindin-D28K between the calcium-loaded and unloaded proteins. The X-ray structure of human calbindin-D28K: an improved model.,Noble JW, Almalki R, Roe SM, Wagner A, Duman R, Atack JR Acta Crystallogr D Struct Biol. 2018 Oct 1;74(Pt 10):1008-1014. doi:, 10.1107/S2059798318011610. Epub 2018 Oct 2. PMID:30289411[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Almalki, R | Atack, J R | Dumanc, R | Noble, J W | Roe, S M | Wagner, A | Buffer | Calcium binding protein | Ef-hand | Impase | Metal binding protein