Catalytic domain of the Serine/Threonine Kinases, Chlamydomonas reinhardtii CNK2 and similar proteins
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. Chlamydomonas reinhardtii CNK2 has both cilliary and cell cycle functions. It influences flagellar length through promoting flagellar disassembly, and it regulates cell size, through influencing the size threshold at which cells commit to mitosis. This subfamily belongs to the (NIMA)-related kinase (Nek) family, which includes seven different Chlamydomonas Neks (CNKs 1-6 and Fa2). This subfamily includes CNK1, and -2. The Nek family 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.