Calmodulin 3D structure

Calmodulin (CaM) is a Ca²⁺-binding protein that is a key component of the Ca²⁺ second-messenger system and is involved in controlling many of the biochemical processes of cells.

Calmodulin is a small, acidic protein approximately 148 amino acids long and, as such, is a favorite for testing protein simulation software. It contains four EF-hand "motifs" or domains, each of which binds a Ca²⁺ ion. It typically binds 0, 2, or 4 calcium ions, and binds and regulates different proteins in each state. There are over a hundred proteins known to bind calmodulin. It is highly conserved across all eukaryotes, 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.

Other calcium-binding proteins

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.

External links

• http://structbio.vanderbilt.edu/cabp_database/general/prot_pages/calmod.html