This PGM-like (phosphoglucomutase-like) protein of unknown function belongs to the alpha-D-phosphohexomutase superfamily and is found in both archaea and bacteria. The alpha-D-phosphohexomutases include several related enzymes that catalyze a reversible intramolecular phosphoryl transfer on their sugar substrates. Other members of this superfamily include phosphoglucosamine mutase (PNGM), phosphoacetylglucosamine mutase (PAGM), the bacterial phosphomannomutase ManB, the bacterial phosphoglucosamine mutase GlmM, and the bifunctional phosphomannomutase/phosphoglucomutase (PMM/PGM). Each of these enzymes has four structural domains (subdomains) with a centrally located active site formed by four loops, one from each subdomain. All four subdomains are included in this alignment model.