Premium
Solution structure and backbone dynamics of Calsensin, an invertebrate neuronal calcium‐binding protein
Author(s) -
Venkitaramani Deepa V.,
Fulton D. Bruce,
Andreotti Amy H.,
Johansen Kristen M.,
Johansen Jørgen
Publication year - 2005
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.051412605
Subject(s) - calcium binding protein , heteronuclear molecule , chemistry , calcium , biophysics , crystallography , protein structure , ef hand , binding protein , binding site , nuclear magnetic resonance spectroscopy , helix (gastropod) , biochemistry , stereochemistry , biology , ecology , organic chemistry , gene , snail
Calsensin is an EF‐hand calcium‐binding protein expressed by a subset of peripheral sensory neurons that fasciculate into a single tract in the leech central nervous system. Calsensin is a 9‐kD protein with two EF‐hand calcium‐binding motifs. Using multidimensional NMR spectroscopy we have determined the solution structure and backbone dynamics of calcium‐bound Calsensin. Calsensin consists of four helices forming a unicornate‐type four‐helix bundle. The residues in the third helix undergo slow conformational exchange indicating that the motion of this helix is associated with calciumbinding. The backbone dynamics of the protein as measured by 15 N relaxation rates and heteronuclear NOEs correlate well with the three‐dimensional structure. Furthermore, comparison of the structure of Calsensin with other members of the EF‐hand calcium‐binding protein family provides insight into plausible mechanisms of calcium and target protein binding.