Starch synthase, catalytic domain <p>This region represents the catalytic domain of glycogen (or starch) synthases that use ADP-glucose (<db_xref db="EC" dbkey="2.4.1.21"/>), rather than UDP-glucose (<db_xref db="EC" dbkey="2.4.1.11"/>) as in animals, as the glucose donor. This enzyme is found in bacteria and plants. Whether the name given is glycogen synthase or starch synthase depends on context, and therefore on substrate.</p>