They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl.
2-Epimerase was discovered as a target because it was one of the enzymes in the biosynthetic pathway for synthesizing an essential neutral polysaccharide in the cell wall of B. anthracis (Glu:Gal-NAc:Man-NAc at a 3:2:1 ratio).
INn Trypanosoma congolense, in vitro analyses of the incorporated sugars after hydrolysis of the glycoprotein showed that glucosamine and mannose are utilized in the biosynthesis of the carbohydrate moiety directly whereas galactose was converted possibly to other intermediates before being incorporated into the antigen.