D184

Kinase Glossary: D184

D184 is a key conserved residue in ePK and most PKL kinases. It is part of the DFG motif. It binds the first Mg++ ion required for catalysis. It is one of three residues (along with K72 and D166) whose absence is used to predict pseudokinases. The CASK kinase has lost D184 and has evolved in animals to be a Mg-inhibited rather than Mg-requiring enzyme. The number 184 is based on the position of this residue in the first PKA kinase crystal, 1ATP.