The

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 ...

tyrosine phenol-lyase ()

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 ...

:L-tyrosine + H₂O

\rightleftharpoons

phenol + pyruvate + NH₃ This enzyme belongs to the family of

lyase In biochemistry, a lyase is an enzyme that catalyzes the breaking (an elimination reaction) of various chemical bonds by means other than hydrolysis (a substitution reaction) and oxidation, often forming a new double bond or a new ring structure. ...

s, specifically in the "catch-all" class of carbon-carbon lyases. The systematic name of this enzyme class is L-tyrosine phenol-lyase (deaminating; pyruvate-forming). Other names in common use include beta-tyrosinase, and L-tyrosine phenol-lyase (deaminating). 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 ...

and

nitrogen metabolism The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biologi ...

. It employs one cofactor,

pyridoxal phosphate Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent ac ...

Structural studies

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

References

* * EC 4.1.99 Pyridoxal phosphate enzymes Enzymes of known structure {{4.1-enzyme-stub