User:Alice Harmon/Sandbox 2

CDPKCDPK

Calcium-dependent protein kinases (CDPKs) are found in plants, algae, and apicomplexan protists, such as the parasites that cause malaria and toxoplasmosis. They are monomeric enzymes containing an amino-terminal protein kinase domain linked to a carboxy-terminal calcium-binding domain, that has sequence similarity to calmodulin. CDPKs belong to the calmodulin-dependent protein kinase family.

Crystal structures of inactive and active conformations of CDPK1 from Toxoplasma gondii show the dramatic conformation change that occurs upon the binding of calcium to the regulatory domain .

spinqualitylabelsall models active TgCDPK1 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

spinqualitylabelsall models inactive TgCDPK1 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

The crystal structure 3hx4 shows that of the kinase that is bound to calcium (green spheres) and the ATP analog ANP (also called AMPPNP) shown in wireframe and CPK coloring. The catalytic domain is blue and the calcium activation domain (CAD) is gold. Note that CAD is bound to the side of the kinase that is opposite of the catalytic cleft, making it available for peptide substrate binding.

The crystal structure 3ku2 shows of the kinase that is bound only to the ANP (wireframe and CPK coloring). As above, the catalytic domain is blue and the calcium activation domain (CAD) is gold. Note the large conformational change in the CAD and that it is bound to the same side of the kinase as the catalytic cleft, blocking it from binding peptide substrate.