Bipartite Ca2+-binding motif in C2 domains of synaptotagmin and protein kinase C.
C2 domains are found in many proteins involved in membrane traffic or signal transduction. Although C2 domains are thought to bind calcium ions, the structural basis for calcium binding is unclear. Analysis of calcium binding to C2 domains of synaptotagmin I and protein kinase C-beta by nuclear magnetic resonance spectroscopy revealed a bipartite calcium-binding motif that involves the coordination of two calcium ions by five aspartate residues located on two separate loops. Sequence comparisons indicated that this may be a widely used calcium-binding motif, designated here as the C2 motif.
Shao
X
X
Department of Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75235, USA.
Davletov
B A
BA
Sutton
R B
RB
Südhof
T C
TC
Rizo
J
J
D001224:Aspartic Acid / Q000737:chemistry; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D011493:Protein Kinase C / Q000737:chemistry / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D050863:Synaptotagmin I; D050857:Synaptotagmins; D013696:Temperature
D002135:Calcium-Binding Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D010743:Phospholipids; D050863:Synaptotagmin I; D050857:Synaptotagmins; D001224:Aspartic Acid; D011493:Protein Kinase C; D002118:Calcium