Proteins containing this domain consist of a novel group of eukaryotic protein kinase catalytic domains, which have no detectable similarity to conventional kinases. Proteins include myosin heavy chain kinases [<cite idref="PUB00007403"/>, <cite idref="PUB00007404"/>] and Elongation Factor-2 kinase and a bifunctional ion channel [<cite idref="PUB00007405"/>].