C2 Domains

**Definition:** Protein modules that function in the targeting of proteins to CELL MEMBRANES. They consist of an eight-stranded anti-parallel beta-sandwich composed of a pair of four-stranded beta-sheets. This structural unit forms a pocket on the membrane-interacting face of the protein and co-ordinates the binding of 2 to 3 calcium ions; however, not all C2 domains bind calcium. Examples of C2 domain-containing proteins include PROTEIN KINASE C and PTEN PHOSPHOHYDROLASE.

**Tree numbers:** - G02.111.570.820.709.275.750.125

**Synonyms:** - C2 Domain