The following text describes a protein:
Function:
Highly reducing polyketide synthase; part of the gene cluster that mediates the biosynthesis of fumonisins B1 (FB1), B2 (FB2), B3 (FB3), and B4 (FB4), which are carcinogenic mycotoxins. The biosynthesis starts with the FUM1-catalyzed carbon chain assembly from one molecule of acetyl-CoA, eight molecules of malonyl-CoA, and two molecules of methionine (in S-adenosyl form). The C18 polyketide chain is released from the enzyme by a nucleophilic attack of a carbanion, which is derived from R-carbon of alanine by decarboxylation, on the carbonyl carbon of polyketide acyl chain. This step is catalyzed by the pyridoxal 5'-phosphate-dependent aminoacyl transferase FUM8. The resultant 3-keto intermediate is then stereospecifically reduced to a 3-hydroxyl product by reductase FUM13. Subsequent oxidations at C-10 by the cytochrome P450 monooxygenase FUM2, C-14 and C-15 by FUM6, FUM12 or FUM15, tricarballylic esterification of the hydroxyl groups on C-14 and C-15 by acyltransferase FUM14, and C-5 hydroxylation by 2-keto-glutarate-dependent dioxygenase FUM3 furnish the biosynthesis of fumonisins. The tricarballylic moieties are most likely derived from the citric acid cycle, and their addition to the carbon backbone may involve FUM7, FUM10, FUM11 and FUM14 (Probable).
Sequence:
MGVIESPSSTTSGSAEEMAQAITGHEDSVLPVAIVGMGMRLPGGIHTPDELWGMLVEKRSTRCEIPPTRFSVDGFHSPSSKPGSIAMRHGHFLDDKDDLHRLDTSFFSMGMTEVSDIDPQQRMLLEVAYECMQSSGQTNWRGSNIGCYVGVWGEDWLDLHSKDLYDSGTYRVSGGHDFAISNRISYEYDLKGPSFTIKAGCSSSLIALHEAVRAIRAGDCDGAIVAGTNLVFSPTMSVAMTEQGVLSPDASCKTFDANANGYARGEAINAIFLKPLNNALREGDPIRALVRATSSNSDGKTPGMSMPSSESHEALIRRAYGEVFLDPKDTCFVEAHGTGTSVGDPLEATAIARVFGGSSDNKLYIGSVKPNLGHSEGASGVSSVMKAVLALENRTIPPNINFSTPNPKIPFSEMNMAVPVDAIPWPRDRPLRVSVNSFGIGGANAHCIIETLEEYLGRSLPNESQVAPIRNGNGSVQADSSSAVTSITAMKMEVRRKKRQSAVEAAGLVSNLRLVADSTKIRPSKALYVLSAANPTSLRQSVMDYQKYLASHKTDPVDVSYTLANRREHLSHRTYGVVTTESTNDTPIVPDFSPLSKTNNNSLPEINMIFTGQGAQWVGMGKELMDEYETFYNTIAYLGLVLSGLEHPPTWDLIRELSRPAESSNVGRAEFSQPLVCAVQVALVDLLRSWGITPAAVVGHSSGEMAAAYAAGAISSEEAITIAYYRGYVNQQYTRDGGMAAIGMGAQEVAPYLVEGVGVACENSPQSVTLSGDKGVLEEVCQKIKEQVPDCFVRQLKVNVAYHSHHMQDLGGLFENLLEGKVYSQSPTIPFFSSVTVQKITEPRSLDAAYWRQNLESPVRFTGAVKLLLEARASTGSKQVFVEIGPHSALSGPLRQIFKAHGRGKEAYVSAMIRGEDCTESLLKLAGELFCHGTSLQLSNVTADGDVVVDLPPYPWNHDREYWSESRVSKDWRFRKFPNHELLGSRTLESSSLQPEWRNLIRLDGIPWLRDHQVLNDVVFPCAGYLAMAVEAVRQVAGTSEIGGFTLKSVVVQSALVLTESKPVEVLTSLRPVRLTNTLDSAWWEFSIVAHNGTSWIKHCEGQVRPGQDAHQKTAVLPQSEPISQHYPRLVDNLYPELLRIGLRYGPSFRGLDNVSCVPNGKKAAAMLRETTVSESSYAIHPTTIDHCLQLFFPASCDGAFYRAEKLCVPTAIGRLYLADGKSCEVESARAEASAATNSGGSISGAATVVSKQNSTLLSLEDGKFSPLEMDLAEDGNADLVGTARLEWKPNLDFADMCSLVRPSHASMNDGPELDLVEQLTLLAILEIHERIDGAVTPGGHDHAHQHIPNFRGWIADQVTAAAEGRYRGVVADAREIASLERGARLSLMTNLRQQVLRTGAASAAVLIGRVVDHCEEIVKGELEGIELLQAEDGLTNYYNYVESRTDSIDFFATAGHTRPTLRVLEIGAGTGGGAQVILEGLTNGKERLFSTYAYTDISAGFFVAAQERFKAYKGLDFKVLDITKDPSEQGFESGSFDLIIAGNVIHATPTLNETLANVRKLLAPEGYLFLQELSPKMRMVNLIMGILPGWWLGAAEGRVEEPYLDPSQWDTVLKETGFSGVDSAIYDAPYPYHLNANIISRPAKESAPQPRAIRGRLTLLHHADDTNSSSITQLREVLDARGLETDMVVFHEHEELKAGEQDVIISLLELKKPFFSSISAAQLESFQRIVAKLGSIEMIWVTRPAQHGLSASDNPGFGLSLGLTRTLRSEQSLAITTLEIDQVNDESFKAVTNLAIKVLDHREGGSTESTRGATTMDPDREYVVENGVVKVARYHPVSLSQELASRASKPEAVTLEIGRMGLLQTLGWVPFPTSDPGYGEVTIEPRCAGLNFRDVLLCMGVVEATGVGIGLEGSGIITKVGAGVGKFQPGDPVFYLADNCFSTQITISAQRCAKIPSQLAFEDAATMPCVYATVIHSLLDVGGLRPGQSILIHSACGGIGIAALNLCRNFQGLEIYTTVGNEEKVQYLVDNFGLPRSRIFNSRDASFLYDVRAATQGRGVDLVLNSLSGDLLHASWQCVAPYGKMLEIGKRDFIGKARLEMDLFEANRSFIGIDLARFDSARCQKLLERTAAMIQTGIVQPIKPVKVFDASDAEGAFRYMQKGVHLGKIVVSIPPHSSTALPITPKPLQVKLNPEASYLLVGGLGGLGRAAATWMVESGARYLIFFSRSAGLSVRDQAFFQELASQGCTAQAVRGDVLNLADVELAMASAPPGKPIRGVLQMSMVLRDKPFADMSLEDWDTAVKPKVHGTWNLHLAAPKDLDFFFATGSISGSFGTPGQANYAAGNTYLTALFEHRRALGLPASVLQIGLIEDIGYLAKNPERAEALRAAGGFFLRTRQLLQGLNWALLSSDPHHPEYQLTIGLRSDKALSDPANRVIWKKDSRAALYHNQEISTDAGAGDDQGINAIRLLVASCEEDPGILEDPATVELVTNEIGKRVCMFMLRPVEEMDPTASLTSLGVDSLVTIEIRNWIKRTFGGVEVSTLEILNSGTIQGLARLTVDGLKARFAASEQTDGDAYLEMKAP