In biochemistry, this is the general name given to a class of enzymes: a transferase is an enzyme that catalyzes the transfer of a functional group (e.g., a methyl or phosphate group) from one molecule (called the donor) to another (called the acceptor). For example, an enzyme that catalyzed this reaction would be a transferase:
- A–X + B → A + B–X
In this example, A would be the donor, and B would be the acceptor. The donor is often a coenzyme.
Some of the most important discoveries relating to transferases occurred in the early 1950s. Earliest discoveries of transferase activity occurred in other classifications of enzymes, including Beta-galactosidase, protease, and acid/base phosphatase. Prior to the realization that individual enzymes were capable of such a task, it was believed that two or more enzymes enacted functional group transfers.
One such example of early transferase reclassification is the discovery and subsequent naming of uridyl transferase. In 1953, the enzyme uridine diphosphoglucose pyrophosphorylase (otherwise known as UDP-glucose pyrophosphorylase) was shown to be a transferase, when it was found that it could reversibly produce uridine triphosphate and glucose 1-phosphate from UDP-glucose and an organic pyrophosphate.
Proper names of transferases are formed as "donor:acceptor grouptransferase." However, other names are much more common. The common names of transferases are often formed as "acceptor grouptransferase" or "donor grouptransferase." For example, a DNA methyltransferase is a transferase that catalyzes the transfer of a methyl group to a DNA acceptor.
Transferases are classified as EC 2 in the EC number classification. Transferases can be further classified into nine subclasses:
- EC 2.1 includes enzymes that transfer one-carbon groups (methyltransferase)
- EC 2.2 includes enzymes that transfer aldehyde or ketone groups
- EC 2.3 includes acyltransferases
- EC 2.4 includes glycosyltransferases
- EC 2.5 includes enzymes that transfer alkyl or aryl groups, other than methyl groups
- EC 2.6 includes enzymes that transfer nitrogenous groups (transaminase)
- EC 2.7 includes enzymes that transfer phosphorus-containing groups (phosphotransferase, including polymerase and kinase)
- EC 2.8 includes enzymes that transfer sulfur-containing groups (sulfurtransferase and sulfotransferase)
- EC 2.9 includes enzymes that transfer selenium-containing groups
Transferase deficiencies are at the root of many common illnesses and diseases. The most common result of a transferase deficiency is a buildup of a cellular product. Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency, for example leads to a buildup of ketones, while carnitine palmitoyltransferase II deficiency leads to an excess long chain fatty acids, as the body lacks the ability to transport fatty acids into the mitochondria to be processed as a fuel source. Galactosemia results from an inability to process galactose, a simple sugar.
Transferases are involved in a myriad of reactions in the cell. Some examples of these reactions include CoA transferase, which transfers thiol esters , N-acetyl transferase which is part of the pathway that metabolizes tryptophan and in the regulation of pyruvate dehydrogenase also known as PDH . The regulation of PDH involves both phosphatases, which remove phosphates, and kinases, which add phosphates
- Queen Mary, University of London
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