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.
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.
As of late 2007, only one structure had been solved for this class of enzymes, with the PDB accession code 1T3I.