The PSEUDOKINASE gene group is a collection kinase domain containing proteins which lack or have been predicted to lack phosphotransferase activity. The list has been compiled from publications and is not a comprehensive list of pseudokinases in D.mel. Pseudokinase classification by primary sequence may be unreliable - a good summary of the problems associated is provided by PMID:21074407.
CASK is thought to be a pseudokinase as it lacks the canonical DFG-motif required for Mg2+-binding in its CaM-kinase domain. In the absence of Mg2+ human CASK was shown to autophosphorylate and to phosphorylate bound neurexin-1 at very low catalytic rate (PMID:18423203). Its inhibition by divalent cations suggests that the kinase is inactive in vivo.