Protein
FAD-dependent monooxygenase OpS4
Organism
Beauveria bassiana (strain ARSEF 2860)
Function
FAD-dependent monooxygenase; part of the gene cluster that mediates the biosynthesis of the bibenzoquinone oosporein, a metabolite required for fungal virulence that acts by evading host immunity to facilitate fungal multiplication in insects (PubMed:26305932). The non-reducing polyketide synthase OpS1 produces orsellinic acid by condensing acetyl-CoA with 3 malonyl-CoA units (PubMed:26305932). Orsellinic acid is then hydroxylated to benzenetriol by the hydroxylase OpS4 (PubMed:26305932). The intermediate is oxidized either nonenzymatically to 5,5'-dideoxy-oosporein or enzymatically to benzenetetrol by the oxidoreductase OpS7 (PubMed:26305932). The latter is further dimerized to oosporein by the catalase OpS5 (PubMed:26305932). OpS6 probably functions en route for protecting cells against oxidative stress by scavenging any leaked free radical form of benzenetetrol by activating the thiol group of glutathione (PubMed:26305932).
Similarity
Belongs to the paxM FAD-dependent monooxygenase family.
Sequence
MGSIREPLHLVVIGGGLAGLSAAIATRLEGHRCTLLEKAPEFNEVGAGLQLTPNSTRLLRRWGVLDKLRSKAGIPTQLTVRRYDGSKVLSRADGWDETMQSQYDAPFWDMHRADLQAAMVARARHLGVDVRTGAEVESIDTDGVAVILAGTRERLQGDVVLAADGLWSRTRAALFPDLGTAPQPTGDLAYRIILRLENLQHDPELAAWVAKPTVNFWVGADAHAVAYSVRGGSELNLVLLCPDDLPEGCARAQADLEEMRARFQGWDPLLCRFLDNVKTVEKWRLMHMPSLPKWNHESGYFTMAGDSCHPMLPYLAQGANSAMEDGAVLGRLLGSIHEASRIPDVLAVYQEIRKVRVEKIAKQALKQRYNFHMPDGPLQEARDEAMTTHQQREEEYASQWTCPIMQPWLYGYDAIAVADSAVANTKL