eEF2K is a calcium calmodulin-dependent alpha kinase that is present in many organisms such as humans, frog, mouse, cattle, rat, and nematode. It phosphorylates eef2 on a serine residue which prevents it from binding to the ribosome, thus, inhibiting translation. eeF2K is yet to be crystallised to determine its structure however, its secondary structure is predicted to have 40% alpha helices, 11% beta sheets and 40% disordered region. Three functional domains namely; a kinase domain, an SEL1-like repeats and a calmodulin-binding domain have also been predicted. There is also a linker region which links the N and C terminus and spans the residues 336-520.

 

The alpha kinase domain, located between residues 116-326, carries out the catalytic activity and is homologous in sequence to dicotystellium myosin heavy chain kinase A (MHCK A). Although its kinase domain does share sequence homology with other kinases, like other kinases it has the glycine rich loop, GXGXXG, which coordinates the phosphate group of ATP in its ATP-binding site. The calmodulin-binding domain which was thought to be C-terminus to the catalytic domain between residues 593-609 however, experiments using the truncated protein has been experimentally shown to be between residues 51-96 which is N-terminus to the catalytic domain. The SEL1-like repeats in the C-terminus are between 571-725 and are suggested to take part in aiding the recognition of eef2.