fungal extracellular capsule synthesizing enzyme antifungal susceptible USX1 UDP-xylose synthase antibiotic_resistance ARO:3009630 UDP-xylose synthase is involved the synthesis of extracellular capsules in some fungi. It also is responsible for the presence of Fcy2 enzyme in the cell membrane, which is the site of import for the antifungal 5-flucytosine.