| cysteine desulfurase | |
| Ec Number: | 2.8.1.7 |
| Go Code: | 0031071 |
In enzymology, a cysteine desulfurase is an enzyme that catalyzes the chemical reaction
L-cysteine + [enzyme]-cysteine
\rightleftharpoons
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.
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.
As of late 2007, only one structure had been solved for this class of enzymes, with the PDB accession code .