Module 4: Figure CaM structure
The EF-hand Ca2+-binding domain.
These ribbon diagrams illustrate the structure of calmodulin in the absence (left) and presence (red balls in the centre and right-hand panels) of Ca2+. When Ca2+ binds, calmodulin (CaM) undergoes a remarkable change in conformation that enables it to wrap around parts of proteins (shown in green on the right) to alter their properties. Such an action is evident in the Ca2+-dependent opening of K+ channels (Module 3: Figure IK/SK channel opening). Reproduced, with permission, from the Annual Review of Pharmacology and Toxicology, Volume 41 ©2001 by Annual Reviews; http://www.annualreviews.org; see Hook and Means 2001.