In enzymology, a cysteine desulfurase (EC 2.8.1.7) is an enzyme that catalyzes the chemical reaction
- 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. One group of authors has given it the acronym hapE, for hydrogen sulfide, alanine, and pyruvate producing enzyme.[1]
This enzyme belongs to the family of transferases, specifically the sulfurtransferases, which transfer sulfur-containing groups. The systematic name of this enzyme class is L-cysteine:[enzyme cysteine] sulfurtransferase. Other names in common use include IscS, NIFS, NifS, SufS, and cysteine desulfurylase.
Function
Bacteria contain cysteine desulfurases to form iron sulfur clusters in proteins.[2] 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.[1]
In mammals, the enzyme participates in thiamine metabolism.
Structural studies
As of late 2007, only one structure had been solved for this class of enzymes, with the PDB accession code 1T3I.
References
- ^ a b Großhennig, Stephanie; Ischebeck, Till; Gibhardt, Johannes; Busse, Julia; Feussner, Ivo; Stülke, Jörg (April 2016). "Hydrogen sulfide is a novel potential virulence factor of M ycoplasma 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.
- ^ 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.
- Zheng L, White RH, Cash VL, Jack RF, Dean DR (1993). "Cysteine desulfurase activity indicates a role for NIFS in metallocluster biosynthesis". Proc. Natl. Acad. Sci. U.S.A. 90 (7): 2754–8. Bibcode:1993PNAS...90.2754Z. doi:10.1073/pnas.90.7.2754. PMC 46174. PMID 8464885.
- Frazzon J, Dean DR (2003). "Formation of iron-sulfur clusters in bacteria: an emerging field in bioinorganic chemistry". Curr. Opin. Chem. Biol. 7 (2): 166–73. doi:10.1016/S1367-5931(03)00021-8. PMID 12714048.
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