KEGG   ENZYME: 4.4.1.35
Entry
EC 4.4.1.35                 Enzyme                                 

Name
L-cystine beta-lyase;
CORI3 (gene name)
Class
Lyases;
Carbon-sulfur lyases;
Carbon-sulfur lyases (only sub-subclass identified to date)
Sysname
L-cystine thiocysteine-lyase (deaminating; pyruvate-forming)
Reaction(IUBMB)
L-cystine + H2O = L-thiocysteine + pyruvate + NH3 (overall reaction) [RN:R02408];
(1a) L-cystine = L-thiocysteine + 2-aminoprop-2-enoate;
(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous);
(1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)
Reaction(KEGG)
R02408
Substrate
L-cystine [CPD:C00491];
H2O [CPD:C00001];
2-aminoprop-2-enoate [CPD:C02218];
2-iminopropanoate [CPD:C20904]
Product
L-thiocysteine [CPD:C01962];
pyruvate [CPD:C00022];
NH3 [CPD:C00014];
2-aminoprop-2-enoate [CPD:C02218];
2-iminopropanoate [CPD:C20904]
Comment
A pyridoxal 5'-phosphate protein. The enzyme cleaves a carbon-sulfur bond, releasing L-thiocysteine and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. The latter reaction, which can occur spontaneously, can also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase. The enzyme from Brassica oleracea var. italica (broccoli) does not act on cysteine or cystathionine.
History
EC 4.4.1.35 created 2017
Pathway
ec00270  Cysteine and methionine metabolism
ec01100  Metabolic pathways
Orthology
K21623  L-cystine beta-lyase
Genes
ATH: AT4G23600(CORI3)
CSAT: 104785741
EUS: EUTSA_v10025296mg
BRP: 103861272
BNA: 106346576 106441358
BOE: 106313559
RSZ: 108821536
THJ: 104803905
Reference
1  [PMID:27396740]
  Authors
Ukai K, Sekiya J
  Title
Purification and Characterization of Cystine Lyase a from Broccoli Inflorescence.
  Journal
Biosci Biotechnol Biochem 61:1890-5 (1997)
DOI:10.1271/bbb.61.1890
Reference
2  [PMID:12525491]
  Authors
Jones PR, Manabe T, Awazuhara M, Saito K
  Title
A new member of plant CS-lyases. A cystine lyase from Arabidopsis thaliana.
  Journal
J Biol Chem 278:10291-6 (2003)
DOI:10.1074/jbc.M212207200
  Sequence
[ath:AT4G23600]
Other DBs
ExplorEnz - The Enzyme Database: 4.4.1.35
IUBMB Enzyme Nomenclature: 4.4.1.35
ExPASy - ENZYME nomenclature database: 4.4.1.35
BRENDA, the Enzyme Database: 4.4.1.35

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