Catalytic domain of Nuclear Dbf2-Related kinase-like Protein Serine/Threonine Kinases
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. NDR kinases regulate mitosis, cell growth, embryonic development, and neurological processes. They are also required for proper centrosome duplication. Higher eukaryotes contain two NDR isoforms, NDR1 and NDR2. This subfamily also contains fungal NDR-like kinases. NDR kinase contains an N-terminal regulatory (NTR) domain and an insert within the catalytic domain that contains an auto-inhibitory sequence. Like many other AGC kinases, NDR kinase requires phosphorylation at two sites, the activation loop (A-loop) and the hydrophobic motif (HM), for activity. The NDR kinase subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.