Nucleotide sugar dehydrogenase <p>Enzymes in this family catalyse the NAD-dependent alcohol-to-acid oxidation of nucleotide-linked sugars. Examples include UDP-glucose 6-dehydrogenase (<db_xref db="EC" dbkey="1.1.1.22"/>) [<cite idref="PUB00042833"/>], GDP-mannose 6-dehydrogenase (<db_xref db="EC" dbkey="1.1.1.132"/>) [<cite idref="PUB00042834"/>], UDP-N-acetylglucosamine 6-dehydrogenase (<db_xref db="EC" dbkey="1.1.1.136"/>) [<cite idref="PUB00042835"/>], UDP-N-acetyl-D-galactosaminuronic acid dehydrogenase [<cite idref="PUB00042836"/>] and UDP-N-acetyl-D-mannosaminuronic acid dehydrogenase [<cite idref="PUB00042837"/>]. These enzymes are most often involved in the biosynthesis of polysaccharides and are often found in operons devoted to that purpose. All of these enzymes contain three domains, <db_xref db="INTERPRO" dbkey="IPR001732"/>, <db_xref db="INTERPRO" dbkey="IPR014026"/>, and <db_xref db="INTERPRO" dbkey="IPR014027"/> for the N-terminal, central, and C-terminal regions respectively.</p>