1c7v
NMR SOLUTION STRUCTURE OF THE CALCIUM-BOUND C-TERMINAL DOMAIN (W81-S161) OF CALCIUM VECTOR PROTEIN FROM AMPHIOXUSNMR 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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