Cysteine lyase

cysteine lyase
Identifiers
EC number	4.4.1.10
CAS number	9079-86-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a cysteine lyase (EC 4.4.1.10) is an enzyme that catalyzes the chemical reaction

L-cysteine + sulfite $\rightleftharpoons$ L-cysteate + hydrogen sulfide

Thus, the two substrates of this enzyme are L-cysteine and sulfite, whereas its two products are L-cysteate and hydrogen sulfide.

This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cysteine hydrogen-sulfide-lyase (adding sulfite L-cysteate-forming). Other names in common use include cysteine (sulfite) lyase, and L-cysteine hydrogen-sulfide-lyase (adding sulfite). This enzyme participates in cysteine metabolism and taurine and hypotaurine metabolism. It employs one cofactor, pyridoxal phosphate.

References

• Tolosa EA, Chepurnova NK, Khomutov RM, Severin ES (1969). "Reactions catalysed by cysteine lyase from the yolk sac of chicken embryo". Biochim. Biophys. Acta 171 (2): 369–71. doi:10.1016/0005-2744(69)90174-0. PMID 5813025.