L-cysteate sulfo-lyase explained

L-cysteate sulfo-lyase
Ec Number:	4.4.1.25

The enzyme L-cysteate sulfo-lyase (EC 4.4.1.25) catalyzes the reaction

L-cysteate + H₂O = hydrogensulfite + pyruvate + NH₃ (overall reaction)

(1a) L-cysteate = hydrogensulfite + 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 lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cysteate bisulfite-lyase (deaminating; pyruvate-forming). Other names in common use include L-cysteate sulfo-lyase (deaminating), and CuyA.

References

• Denger K, Smits TH, Cook AM . 2006 . L-Cysteate sulpho-lyase, a widespread pyridoxal 5′-phosphate-coupled desulphonative enzyme purified from Silicibacter pomeroyi DSS-3(T) . Biochem. J. . 394 . 657 - 64 . 16302849 . 10.1042/BJ20051311 . Pt 3 . 1383715 .