Alliinase

Alliinase_C
crystal structure of alliinase from garlic- apo form
Identifiers
Symbol	Alliinase_C
Pfam	PF04864
Pfam clan	CL0061
InterPro	IPR006948
SCOP	1lk9
SUPERFAMILY	1lk9
Available protein structures: Pfam structures PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

Alliinase EGF-like domain
crystal structure of alliinase from garlic- apo form
Identifiers
Symbol	EGF_alliinase
Pfam	PF04863
Pfam clan	CL0001
InterPro	IPR006947
SCOP	1lk9
SUPERFAMILY	1lk9
Available protein structures: Pfam structures PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

In enzymology, an alliin lyase (EC 4.4.1.4) is an enzyme that catalyzes the chemical reaction

Hence, this enzyme has one substrate, S-alkyl-L-cysteine S-oxide, and two products, alkyl sulfenate and 2-aminoacrylate.

This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is S-alkyl-L-cysteine S-oxide alkyl-sulfenate-lyase (2-aminoacrylate-forming). Other names in common use include alliinase, cysteine sulfoxide lyase, alkylcysteine sulfoxide lyase, S-alkylcysteine sulfoxide lyase, L-cysteine sulfoxide lyase, S-alkyl-L-cysteine sulfoxide lyase, and alliin alkyl-sulfenate-lyase. It employs one cofactor, pyridoxal phosphate.

Many alliinases contain a novel N-terminal epidermal growth factor-like domain (EGF-like domain).

These enzymes are found in plants of the genus Allium, such as garlic and onions. Alliinase is responsible for catalyzing chemical reactions that produce the volatile chemicals that give these foods their flavors, odors, and tear-inducing properties. Alliinases are part of the plant's defense against herbivores. Alliinase is normally sequestered within a plant cell, but, when the plant is damaged by a feeding animal, the alliinase is released to catalyze the production of the pungent chemicals. This tends to have a deterrent effect on the animal. The same reaction occurs when onion or garlic is cut with a knife in the kitchen.