Catalytic domain of Suppressor of loss of cAMP-dependent protein kinase-like Serine/Threonine Kinases
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily is composed of Schizosaccharomyces pombe Sck1 and similar fungal proteins. Sck1 plays a role in trehalase activation triggered by glucose and a nitrogen source. Trehalase catalyzes the cleavage of the disaccharide trehalose to glucose. Trehalose, as a carbohydrate reserve and stress metabolite, plays an important role in the response of yeast to environmental changes. The Sck1-like 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.