This family consists of UDP-N-acetylglucosamine 2-epimerases EC:5.1.3.14 this enzyme catalyzes the production of UDP-ManNAc from UDP-GlcNAc. Note that some of the enzymes is this family are bifunctional, in these instances Pfam matches only the N-terminal half of the protein suggesting that the additional C-terminal part (when compared to mono-functional members of this family) is responsible for the UPD-N-acetylmannosamine kinase activity of these enzymes. This hypothesis is further supported by the assumption that the C-terminal part of rat Gne is the kinase domain.