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4.4.1.35 |
Description |
L-cystine β-lyase |
Alternative names |
cystine C-S lyase; C-DES. |
Catalyzed reaction |
L-cystine + H(2)O = L-thiocysteine + pyruvate + NH(3) (overall reaction)
(1a) L-cystine = L-thiocysteine + 2-aminoprop-2-enoate
(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
(1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)
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Cofactor |
Pyridoxal-phosphate. |
Comments |
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. |
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Different from cysteine desulfurase (EC 2.8.1.7), in that the favorite substrate is cystine and the product persulfide is not protein-bound.
The reaction is carried out also by cystathionine beta-lyase (EC 4.4.1.8).
Cystine lyase enzymes have been described in cyanobacteria (C-DES) and in plants.
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PDB |
1N2T; |
Organisms |
-Eubacteria -Plants |
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Family |
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Links |
Enzyme (activities) 4.4.1.35
BRENDA (activities) 4.4.1.35
KEGG (pathways) 4.4.1.35
PLPMDB (PLP mutants) 4.4.1.35
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References |
Munt O, Prüfer D, Schulze Gronover C. (2013) A novel C-S lyase from the latex-producing plant Taraxacum brevicorniculatum displays alanine aminotransferase and l-cystine lyase activity. J Plant Physiol. 170 33-40. Kessler D. (2006) Slr0077 of Synechocystis has cysteine desulfurase as well as cystine lyase activity Biochem Biophys Res Commun 320 571-7. Jones, P.R.; Manabe, T.; Awazuhara, M.; Saito, K. (2003) A new member of plant CS-lyases. A cystine lyase from Arabidopsis thaliana J Biol Chem 278 10291-6. Kaiser, J.T.; Bruno, S.; Clausen, T.; Huber, R.; Schiaretti, F.; Mozzarelli, A.; Kessler, D.
(2003) Snapshots of the cystine lyase C-DES during catalysis. Studies in solution and in the crystalline state J Biol Chem 278 357-65. Lang, T.; Kessler, D. (1999) Evidence for cysteine persulfide as reaction product of L-Cyst(e)ine C-S-lyase (C-DES) from Synechocystis. Analyses using cystine analogues and recombinant C-DES J Biol Chem 274 189-95. Articles on 4.4.1.35 |
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last changed |
2018/03/21 13:08 |
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