Recoverin is a protein that acts as a calcium sensor in retinal rod cells. This protein controls the lifetime of photoexcited rhodopsin by inhibiting rhodopsin kinase. At the amino-terminal of recoverin is a covalently attached myristoyl group. Recoverin binds two calcium ions (white). This binding leads recoverin from the cytosol to the disc membrane. Like calmodulin, recoverin has 4 EF-hands. These EF-hands play a role in calcium-myristoyl switches which seems to be a long standing method used to control calcium-sensitive processes.
Recoverin is 202 amino acid residues long. It consists of 11 right-handed alpha helices (purple), 2 310 alpha helices (red), and 2 beta-strands (blue). One myristoyl group is shown as well (green).