NMR-driven secondary and tertiary structure model of Ca2+-loaded calexcitin.
Calexcitin (CE) is a Ca2+-binding protein which is expressed in neuronal cells and is a member of the sarcoplasmic Ca2+-binding protein subfamily. The peptide backbone of Ca2+-CE has been assigned by NMR and it shows that CE is composed of nine alpha-helices-forming four EF-hands and an additional helix near the C-terminus. A structural model of CE suggests the presence of a putative recessed hydrophobic pocket that may be involved in Ca2+-mediated protein-ligand interactions. This feature is unique to CE and is absent in other SCPs, such as those from Branchiostoma and Nereis, and from calerythrin.
Gombos
Zoltan
Z
Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, Ont., Canada M5G 1L7. zoltan.gombos@nrc-cnrc.gc.ca
Yap
Kyoko L
KL
Ikura
Mitsuhiko
M
Chakrabartty
Avijit
A
D001665:Binding Sites; D029742:Caenorhabditis elegans Proteins / Q000032:analysis / Q000737:chemistry*; D002118:Calcium / Q000032:analysis / Q000737:chemistry*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000737:chemistry*; D003198:Computer Simulation; D019204:GTP-Binding Proteins / Q000032:analysis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
D029742:Caenorhabditis elegans Proteins; D002135:Calcium-Binding Proteins; D019204:GTP-Binding Proteins; C102751:cex-2 protein, C elegans; D002118:Calcium