enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, a 3,4-dihydroxyphenylacetate 2,3-dioxygenase () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that

catalyzes Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

:3,4-dihydroxyphenylacetate + O₂

\rightleftharpoons

2-hydroxy-5-carboxymethylmuconate semialdehyde Thus, the two substrates of this enzyme are 3,4-dihydroxyphenylacetate and O₂, whereas its product is 2-hydroxy-5-carboxymethylmuconate semialdehyde. This enzyme belongs to the family of

oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ut ...

s, specifically those acting on single donors with O₂ as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O₂. The systematic name of this enzyme class is 3,4-dihydroxyphenylacetate:oxygen 2,3-oxidoreductase (decyclizing). Other names in common use include 3,4-dihydroxyphenylacetic acid 2,3-dioxygenase, HPC dioxygenase, and homoprotocatechuate 2,3-dioxygenase. This enzyme participates in

tyrosine metabolism -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Gr ...

. It employs one cofactor,

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

Structural studies

As of late 2007, eight structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , and .

References

* * * {{Portal bar, Biology, border=no EC 1.13.11 Iron enzymes Enzymes of known structure