Phosphorylates both N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) at similar rates. Involved in the lacto-N-biose I/galacto-N-biose (LNB/GNB) degradation pathway, which is important for host intestinal colonization by bifidobacteria. Also accepts GTP and ITP as phosphate donors. In vitro, can phosphorylate several GlcNAc and GalNAc derivatives. ATP + N-acetyl-D-hexosamine = ADP + H(+) + N-acetyl-alpha-D-hexosamine 1-phosphate kcat is 1.21 sec(-1) for GlcNAc. kcat is 0.752 sec(-1) for GalNAc. Optimum pH is 8.5. Stable at pH 5.0 to 9.5 at 30 degrees Celsius. Optimum temperature is 40 degrees Celsius. Belongs to the protein kinase superfamily.