The enzyme is a member of the flavin-dependent monooxygenase (FMO) family (cf. EC 18.104.22.168). The plant Arabidopsis thaliana contains five isoforms. GS-OX1 through GS-OX4 are able to catalyse the S-oxygenation independent of chain length, while GS-OX5 is specific for 8-(methylthio)octyl glucosinolate.
Hansen, B.G., Kliebenstein, D.J. and Halkier, B.A. Identification of a flavin-monooxygenase as the S-oxygenating enzyme in aliphatic glucosinolate biosynthesis in Arabidopsis. Plant J.50 (2007) 902–910. [PMID: 17461789]
Li, J., Hansen, B.G., Ober, J.A., Kliebenstein, D.J. and Halkier, B.A. Subclade of flavin-monooxygenases involved in aliphatic glucosinolate biosynthesis. Plant Physiol.148 (2008) 1721–1733. [PMID: 18799661]