Calmodulin is a Ca2+-binding protein that is a key component of the Ca2+ second-messenger system and is involved in the regulation of many biochemical and physiological processes.
Calmodulin is a small, acidic protein approximately 148 amino acids long and, as such, is a favorite for testing protein simulation software. It is highly conserved across species, and its expression is essential for biological cells to progress through mitosis.
Calmodulin-stimulated protein phosphatase (EC 3.1.3.16) is the major calmodulin-binding protein in the brain.
Calmodulin belongs to one of the two main groups of calcium-binding proteins, called EF hand proteins. The other group, called annexins[?], bind calcium and phospholipid (e.g., lipocortin[?]). Many other proteins bind calcium, although binding calcium may not be considered their principal function in the cell.
http://structbio.vanderbilt.edu/cabp_database/general/prot_pages/calmod.html
