1c7v
From Proteopedia
NMR SOLUTION STRUCTURE OF THE CALCIUM-BOUND C-TERMINAL DOMAIN (W81-S161) OF CALCIUM VECTOR PROTEIN FROM AMPHIOXUS
Structural highlights
FunctionCAVP_BRALA The exact function of this protein is not yet known. It interacts with CAVPT, a protein also of unknown function, in a calcium-dependent way. This protein 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 PubMedCalcium vector protein (CaVP) from amphioxus is a two-domain, calcium-binding protein (18.3 kDa) of the calmodulin superfamily. Only two of the four EF-hand motifs (sites III and IV) have a significant binding affinity for calcium ions. We determined the solution structure of the domain containing these active sites (C-CaVP: W81-S161), in the Ca(2+)-saturated state, using NMR spectroscopy and restrained molecular dynamics. The tertiary structure is similar to other Ca(2+)-binding domains containing a pair of EF-hand motifs. The apo state has spectroscopic and thermodynamic characteristics of a molten globule, with conserved secondary structure but highly fluctuating tertiary organization. Titration of C-CaVP with Ca(2+) revealed a stepwise ion binding, with a stable equilibrium intermediate in which only site III binds a calcium ion. Despite a highly fluctuating structure of the free site IV, the calcium-bound site III has a persistent structure, with similar secondary elements but different interhelix angle and hydrophobic packing relative to the fully calcium-saturated state. Sequential calcium binding to the regulatory domain of calcium vector protein reveals functional asymmetry and a novel mode of structural rearrangement.,Theret I, Baladi S, Cox JA, Sakamoto H, Craescu CT Biochemistry. 2000 Jul 11;39(27):7920-6. PMID:10891072[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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