A divalent cation is required for activity. UDP-sugar is the best substrate, although other nucleoside-sugar diphosphates are used as substrates with similar Km values but much lower maximum velocities. Thus, this enzyme has a specificity distinct from that of ADP-sugar diphosphatase (EC 184.108.40.206). Some but not all enzymes of this class also appear to have 5'-nucleotidase (see EC 220.127.116.11) activity.
encoded by the gene ushB, that is nonhomologous to the gene ushA, that encodes the enzyme from Escherichia coli. Salmonella typhimurium also contains a silent allel of the gene ushA, i.e. ushA0; Salmonella enterica serotype typhimurium
endogenous UDP-sugar hydrolase activity not detectable before the shift to phosphate-free medium; UDP-sugar hydrolase activity detectable in cell extracts of phosphate-starved wild-type delta-ushA cells