IUBMB Enzyme Nomenclature


Accepted name: isethionate sulfite-lyase

Reaction: isethionate = acetaldehyde + sulfite

Glossary: isethionate = 2-hydroxyethanesulfonate

Other name(s): islA (gene name)

Systematic name: isethionate sulfite-lyase

Comments: The enzyme, characterized from the human gut bacterium Bilophila wadsworthia, participates in a taurine degradation pathway that leads to sulfide production. The active form of the enzyme contains a glycyl radical that is generated by a dedicated activating enzyme via chemistry involving S-adenosyl-L-methionine (SAM) and a [4Fe-4S] cluster.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Peck, S.C., Denger, K., Burrichter, A., Irwin, S.M., Balskus, E.P. and Schleheck, D. A glycyl radical enzyme enables hydrogen sulfide production by the human intestinal bacterium Bilophila wadsworthia. Proc. Natl. Acad. Sci. USA 116 (2019) 3171-3176. [PMID: 30718429]

2. Xing, M., Wei, Y., Zhou, Y., Zhang, J., Lin, L., Hu, Y., Hua, G.,, N. Nanjaraj Urs, A., Liu, D., Wang, F., Guo, C., Tong, Y., Li, M., Liu, Y., Ang, E.L., Zhao, H., Yuchi, Z. and Zhang, Y. Radical-mediated C-S bond cleavage in C2 sulfonate degradation by anaerobic bacteria. Nat. Commun. 10 (2019) 1609. [PMID: 30962433]

[EC created 2021]

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