Enzyme nomenclature and classification: the state of the art

Abstract

The IUBMB enzyme classification system, available at the IUBMB ExplorEnz website, uses a four‐component number (the EC number) that identifies an enzyme in terms of reaction catalysed. There were originally six recognized groups of enzymes: Oxidoreductases (EC 1), Transferases (EC 2), Hydrolases (EC 3), Lyases (EC 4), Isomerases (EC 5) and Ligases (EC 6). Of these, the lyases, which are defined as ‘enzymes that cleave C‐C, C‐O, C‐N and other bonds by means other than by hydrolysis or oxidation’, present particular recognition and classification problems. Recently, a new class, the Translocases (EC 7), has been added, which incorporates enzymes that catalyse the movement of ions or molecules across membranes or their separation within membranes. A new subclass of the isomerases has also been included for those enzymes that alter the conformations of proteins and nucleic acids. Newly reported enzymes are being regularly added to the list after validation and where new information affects the classification of an existing entry, a new EC number is created, but the old one is not reused.

Selective Biocatalytic Defunctionalization of Raw Materials

“…The great advances for biocatalysts, which have already been achieved or can be developed in the future with breakthrough technologies, bring biocatalysts in a favorable position for the mild and selective removal of specific oxygen‐ and nitrogen‐containing functional groups. The unique classification system of the Enzyme Commission (EC Number) for enzymes according to the catalyzed reaction [207] as well as the use of databases and information/communication technologies for a growing number of characterized enzyme structures [208] and enzyme functions [209] provide a valuable scientific infrastructure.…”

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

“…For instance, helpful information can be found in the relevant metabolic pathways described on KEGG [18], kinetic data on BRENDA [19], thermodynamic data on NIST [20], However, the system presents room for improvement, because it is not always unambiguous. In fact, new classes are constantly being added to the EC system, and it should also be noted that non-physiologically occurring enzymes are not included [17]. For these reasons, many other databases can be useful to complement the ExplorEnz information.…”

“…However, the system presents room for improvement, because it is not always unambiguous. In fact, new classes are constantly being added to the EC system, and it should also be noted that non-physiologically occurring enzymes are not included [ 17 ]. For these reasons, many other databases can be useful to complement the ExplorEnz information.…”

Complexity reduction and opportunities in the design, integration and intensification of biocatalytic processes for metabolite synthesis

“…Enzymes have traditionally been classified into six main classes which is based on the type of reaction that they catalyze. This first classification was introduction by Dixon and Webb and was establishment as a fundamental enzyme classification scheme by the enzyme commission more than 60 years ago (McDonald and Tipton, 2022). However a major change of the system was introduced by the enzyme commission in 2018 with the establishment of a new seventh class named as translocases describing enzymes catalyzing transport across cell membranes (McDonald and Tipton, 2022).…”

“…This first classification was introduction by Dixon and Webb and was establishment as a fundamental enzyme classification scheme by the enzyme commission more than 60 years ago (McDonald and Tipton, 2022). However a major change of the system was introduced by the enzyme commission in 2018 with the establishment of a new seventh class named as translocases describing enzymes catalyzing transport across cell membranes (McDonald and Tipton, 2022). The concept of enzyme engineering for optimization of a particular process is now generally accepted.…”