The enzyme cysteine-''S''-conjugate β-lyase (EC 4.4.1.13) catalyzes 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 ...

:an L-cysteine-''S''-conjugate + H₂O = a thiol + NH₃ + pyruvate (overall reaction) ::(1a) an L-cysteine-''S''-conjugate = a thiol + 2-aminoprop-2-enoate ::(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous) ::(1c) 2-iminopropanoate + H₂O = pyruvate + NH₃ (spontaneous) 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 the class of carbon-sulfur lyases. The

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

of this enzyme class is L-cysteine-''S''-conjugate thiol-lyase (deaminating; pyruvate-forming). Other names in common use include cysteine conjugate β-lyase, glutamine transaminase K/cysteine conjugate β-lyase, and L-cysteine-''S''-conjugate thiol-lyase (deaminating). 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, 3

structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

have been solved for this class of enzymes, with PDB accession codes , , and .

References

* EC 4.4.1 Pyridoxal phosphate enzymes Enzymes of known structure {{lyase-stub