In enzymology, a tetrachloroethene reductive dehalogenase is an enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 that catalyzes

Catalysis

Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....

 the chemical reaction

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

trichloroethene + chloride + acceptor tetrachloroethene + reduced acceptor

The 3 substrates

Substrate (biochemistry)

In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...

 of this enzyme are trichloroethene, chloride

Chloride

The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...

, and acceptor

Electron acceptor

An electron acceptor is a chemical entity that accepts electrons transferred to it from another compound. It is an oxidizing agent that, by virtue of its accepting electrons, is itself reduced in the process....

, whereas its two products

Product (chemistry)

Product are formed during chemical reactions as reagents are consumed. Products have lower energy than the reagents and are produced during the reaction according to the second law of thermodynamics. The released energy comes from changes in chemical bonds between atoms in reagent molecules and...

 are tetrachloroethene and reduced acceptor.

This enzyme belongs to the family of oxidoreductase

Oxidoreductase

In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another...

s. The systematic name of this enzyme class is acceptor:trichloroethene oxidoreductase (chlorinating). This enzyme is also called tetrachloroethene reductase. This enzyme participates in tetrachloroethene degradation.

Note that the physiologically relevant reaction actually occurs in the reverse direction from that shown above. In other words, in the bacterial species where this enzyme is found, tetrachloroethene is reductively dechlorinated to trichloroethene and chloride.

This enzyme is one member of a family of enzymes including trichloroethene dehalogenase and vinyl chloride dehalogenase. The other members of this family do not have their own EC numbers at present.