This CD includes PGM2 (phosphoglucomutase 2) and PGM2L1 (phosphoglucomutase 2-like 1). The mammalian PGM2 is thought to be a phosphopentomutase that catalyzes the conversion of the nucleoside breakdown products, ribose-1-phosphate and deoxyribose-1-phosphate to the corresponding 5-phosphopentoses. PGM2L1 is thought to catalyze the 1,3-bisphosphoglycerate-dependent synthesis of glucose 1,6-bisphosphate and other aldose-bisphosphates that serve as cofactors for several sugar phosphomutases and possibly also as regulators of glycolytic enzymes. PGM2 and PGM2L1 belong to the alpha-D-phosphohexomutase superfamily which includes 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 domains with a centrally located active site formed by four loops, one from each domain. All four domains are included in this alignment model.