N-acetyl-D-glucosamine kinase (NAGK)

Converts endogenous N-acetylglucosamine (GlcNAc), a major part of complex carbohydrates, from lysosomal degradation or nutritional sources into GlcNAc 6-phosphate. Involved from the N-glycolylneuraminic acid (Neu5Gc) degradation pathway: although human isn't able to catalyze formation of Neu5Gc due to the inactive CMAHP enzyme, Neu5Gc is present in food and have to be degraded.

Also has ManNAc kinase activity. .