Cysteine desulfurase
| cysteine desulfurase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.8.1.7 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
In enzymology, a cysteine desulfurase (EC 2.8.1.7) is an enzyme that catalyzes the chemical reaction:[1]
- L-cysteine + [enzyme]-cysteine L-alanine + [enzyme]-S-sulfanylcysteine
Thus, the two substrates of this enzyme are L-cysteine and [enzyme]-cysteine, whereas its two products are L-alanine and [enzyme]-S-sulfanylcysteine, the hydropersulfide of the active site cysteine. One group of authors has given it the acronym hapE, for hydrogen sulfide, alanine, and pyruvate producing enzyme,[2] as hydropersulfides are readily reduced to produce hydrogen sulfide.
These enzymes belong to the family of transferases, specifically the sulfurtransferases, which transfer sulfur-containing groups. This function is critical for the assembly of iron-sulfur cluster-containing proteins. The systematic name of this enzyme class is L-cysteine:[enzyme cysteine] sulfurtransferase. These proteins are also known as cysteine desulfurylases.
Known cysteine desulfurases in prokaryotes include IscS (UniProt accession: P0A6B7), NifS (UniProt accession: P05341), and SufS (UniProt accession: P0A6B7).[3] These are named after the corresponding iron-sulfur cluster assembly pathways: nitrogen fixation (NIF), iron-cluster assembly (ISC) and sulfur assimilation (SUF). All three proteins are very similar in structure, however SufS is mechanistically distinct from NifS and IscS.[4] In the mitochondria of mammalian cells, NFS1 acts as the primary cysteine desulfurase.
Function
Bacteria and mitochondria contain cysteine desulfurases to form iron sulfur clusters in proteins.[5] However recently it has been shown that the enzyme, which produces hydrogen sulfide from cysteine, is also a virulence factor, namely for M.pneumoniae, in that it causes both α-hemolysis and β-haemolysis of red blood cells.[2]
IscS participates in bacterial thiamine metabolism by transfer of its hydropersulfide sulfur to the sulfur carrier protein ThiS.[6]
Structural studies
As of late 2007, only one structure had been solved for this class of enzymes, with the PDB accession code PDB: 1T3I. Currently, there are structures for NifS, IscS, SufS, and NFS1 from various species, as well as structures with bound PLP and the hydropersulfide intermediate.[7]
References
- ↑ Zheng, L.; White, R. H.; Cash, V. L.; Jack, R. F.; Dean, D. R. (1993-04-01). "Cysteine desulfurase activity indicates a role for NIFS in metallocluster biosynthesis". Proceedings of the National Academy of Sciences of the United States of America. 90 (7): 2754–2758. doi:10.1073/pnas.90.7.2754. ISSN 0027-8424. PMC 46174. PMID 8464885.
- 1 2 Großhennig, Stephanie; Ischebeck, Till; Gibhardt, Johannes; Busse, Julia; Feussner, Ivo; Stülke, Jörg (April 2016). "Hydrogen sulfide is a novel potential virulence factor of Mycoplasma pneumoniae : characterization of the unusual cysteine desulfurase/desulfhydrase HapE". Molecular Microbiology. 100 (1): 42–54. doi:10.1111/mmi.13300. ISSN 0950-382X. PMID 26711628.
- ↑ Frazzon, Jeverson; Dean, Dennis R (2003-04-01). "Formation of iron–sulfur clusters in bacteria: an emerging field in bioinorganic chemistry". Current Opinion in Chemical Biology. 7 (2): 166–173. doi:10.1016/S1367-5931(03)00021-8. ISSN 1367-5931.
- ↑ Fujishiro, Takashi; Nakamura, Ryosuke; Kunichika, Kouhei; Takahashi, Yasuhiro (2022). "Structural diversity of cysteine desulfurases involved in iron-sulfur cluster biosynthesis". Biophysics and Physicobiology. 19: 1–18. doi:10.2142/biophysico.bppb-v19.0001. ISSN 2189-4779. PMC 8918507. PMID 35377584.
- ↑ Mihara H, Esaki N (2002). "Bacterial cysteine desulfurases: their function and mechanisms". Appl. Microbiol. Biotechnol. 60 (1–2): 12–23. doi:10.1007/s00253-002-1107-4. PMID 12382038. S2CID 23172939.
- ↑ Xi, Jun; Ge, Ying; Kinsland, Cynthia; McLafferty, Fred W.; Begley, Tadhg P. (2001-07-17). "Biosynthesis of the thiazole moiety of thiamin in Escherichia coli: Identification of an acyldisulfide-linked protein–protein conjugate that is functionally analogous to the ubiquitin/E1 complex". Proceedings of the National Academy of Sciences. 98 (15): 8513–8518. doi:10.1073/pnas.141226698. PMC 37467. PMID 11438688.
- ↑ "InterPro". www.ebi.ac.uk. Retrieved 2026-07-05.