EC - L-cysteine desulfidase

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IntEnz Enzyme Nomenclature


Accepted name:
L-cysteine desulfidase
Other name:
L-cysteine desulfhydrase
Systematic name:
L-cysteine sulfide-lyase (deaminating; pyruvate-forming)



The enzyme from the archaeon Methanocaldococcus jannaschii contains a [4Fe-4S] cluster and is specific for L-cysteine (cf. EC, cystathionine γ-lyase). It cleaves a carbon-sulfur bond 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 same reaction can also be catalysed by some pyridoxal-phosphate proteins (cf. EC, cystathionine γ-lyase).

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (10) [show] [UniProt]


  1. Tchong, S. I., Xu, H., White, R. H.
    L-cysteine desulfidase: an [4Fe-4S] enzyme isolated from Methanocaldococcus jannaschii that catalyzes the breakdown of L-cysteine into pyruvate, ammonia, and sulfide.
    Biochemistry 44 : 1659-1670 (2005). [PMID: 15683250]

[EC created 2014]