Source:http://linkedlifedata.com/resource/umls/id/C0022202
MSH: A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.,NCI: An enzyme that transfers functional groups to catalyze the geometric or structural rearrangement of atoms within a given molecule to form an isomer of the original molecule.