. "Catalysis of the reaction: UDP-L-arabinose = UDP-alpha-D-xylose." . . "UDP-arabinose 4-epimerase activity" . "UDP arabinose epimerase activity" . "UDP-D-xylose 4-epimerase activity" . "UDP-D-xylose-4-epimerase activity" . "UDP-L-arabinose 4-epimerase activity" . "UDParabinose 4-epimerase activity" . "uridine 5'-diphosphate-D-xylose 4-epimerase activity" . "uridine diphosphoarabinose epimerase activity" . . .