UDP-galactopyranose mutase (<db_xref db="EC" dbkey="5.4.99.9"/>) is involved in the conversion of UDP-GALP into UDP-GALF through a 2-keto intermediate, and contains FAD as a cofactor. The gene is known as glf, ceoA, and rfbD. It is known experimentally in <taxon tax_id="562">Escherichia coli</taxon>, <taxon tax_id="1773">Mycobacterium tuberculosis</taxon>, and <taxon tax_id="573">Klebsiella pneumoniae</taxon>.