A generally accepted scheme for enzyme classification, as recommended by the International Union of Biochemistry. The first number shows the broad type of enzyme (1, oxidoreductase; 2, transferase; 3, hydrolase; 4, lyase; 5, isomerase; 6, ligase (synthetase). The second and third numbers indicate subsets within these broad categories, and the last number, unique to each enzyme, is assigned arbitrarily.
http://www.chem.qmul.ac.uk/iubmb/enzyme/ E classification database.
Subjects: Medicine and Health.