Mutarotase converts alpha-aldose to the beta-anomer. It is active on D-glucose, L-arabinose, D-xylose, D-galactose, maltose and lactose (By similarity). UDP-alpha-D-glucose = UDP-alpha-D-galactose alpha-D-glucose = beta-D-glucose Carbohydrate metabolism; galactose metabolism. Carbohydrate metabolism; hexose metabolism. By xylose. In the N-terminal section; belongs to the NAD(P)-dependent epimerase/dehydratase family. In the C-terminal section; belongs to the aldose epimerase family.