Isomerases
These enzymes (code EC 5) catalyze geometric or structural changes within a molecule. According to the type of isomerism, they may be called racemases, epimerases, cis-trans isomerases (5.2), isomerases, tautomerases, mutases or cyclo- isomerases. EC 5.1 are racemases or epimerases, EC 5.1.1 indicates acting on amino acids and derivatives and so on.