<p> Synonym: UDP-galactose 4-epimerase UDP-glucose 4-epimerase (<db_xref db="EC" dbkey="5.1.3.2"/>) interconverts UDP-glucose and UDP-galactose which are precursors of glucose- andgalactose-containing exopolysaccharides (EPS). A set of related proteins, someof which are tentatively identified as UDP-glucose-4-epimerase in <taxon tax_id="2336">Thermotoga maritima</taxon>, <taxon tax_id="86665">Bacillus halodurans</taxon>, and several archaea, but deeply branched from this set and lacking experimental evidence, are excluded and described by a separate model.</p>