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B6db activities: 4.4.1.28

4.4.1.28
Description L-cysteine desulfidase
Alternative names L-cysteine desulfhydrase;
cystalysin;
C-S lyase (ambiguous).
Catalyzed reaction L-Cysteine + H(2)O = pyruvate + H(2)S + NH(3)
Cofactor Pyridoxal-phosphate or [4Fe-4S] cluster.
Comments It cleaves a carbon-sulfur bound releasing sulfide and the unstable enamine product 2-aminoprop-2-enoate that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. The reaction can be catalysed by other pyridoxal-phosphate proteins (cf. EC 4.4.1.1, cystathionine γ-lyase).
The enzyme from the archaeon Methanocaldococcus jannaschii contains a [4Fe-4S] cluster instead of PLP.
The validated PLP-dependent enzymes that catalyze this reaction also show cystathionine beta-lyase activity (E.C. 4.4.1.8) and sometimes methionine gamma-lyase activity (4.4.1.11).
PDB 1C7O;
Organisms -Eubacteria -Archea
 
 
Links Enzyme (activities) 4.4.1.28
BRENDA (activities) 4.4.1.28
KEGG (pathways) 4.4.1.28
PLPMDB (PLP mutants) 4.4.1.28
 
References Articles on 4.4.1.28
 
last changed 2019/06/20 13:29

B6db activities