ID   CTB9_CERBT              Reviewed;         324 AA.
AC   A0A2G5I8W0;
DT   17-JUN-2020, integrated into UniProtKB/Swiss-Prot.
DT   31-JAN-2018, sequence version 1.
DT   25-MAY-2022, entry version 13.
DE   RecName: Full=Hydroxylase/desaturase CTB9 {ECO:0000303|PubMed:29844193};
DE            EC=1.-.-.- {ECO:0000305|PubMed:29844193};
DE   AltName: Full=Cercosporin toxin biosynthesis cluster protein 9 {ECO:0000303|PubMed:29844193};
GN   Name=CTB9 {ECO:0000303|PubMed:29844193}; ORFNames=CB0940_00842;
OS   Cercospora beticola (Sugarbeet leaf spot fungus).
OC   Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Dothideomycetes;
OC   Dothideomycetidae; Mycosphaerellales; Mycosphaerellaceae; Cercospora.
OX   NCBI_TaxID=122368;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA], FUNCTION, DISRUPTION
RP   PHENOTYPE, AND PATHWAY.
RC   STRAIN=09-40;
RX   PubMed=29844193; DOI=10.1073/pnas.1712798115;
RA   de Jonge R., Ebert M.K., Huitt-Roehl C.R., Pal P., Suttle J.C.,
RA   Spanner R.E., Neubauer J.D., Jurick W.M. II, Stott K.A., Secor G.A.,
RA   Thomma B.P.H.J., Van de Peer Y., Townsend C.A., Bolton M.D.;
RT   "Gene cluster conservation provides insight into cercosporin biosynthesis
RT   and extends production to the genus Colletotrichum.";
RL   Proc. Natl. Acad. Sci. U.S.A. 115:E5459-E5466(2018).
RN   [2]
RP   REVIEW ON CERCOSPORIN.
RX   PubMed=11701851; DOI=10.1146/annurev.phyto.38.1.461;
RA   Daub M.E., Ehrenshaft M.;
RT   "The photoactivated cercospora toxin cercosporin: contributions to plant
RT   disease and fundamental biology.";
RL   Annu. Rev. Phytopathol. 38:461-490(2000).
CC   -!- FUNCTION: Hydroxylase/desaturase; part of the gene cluster that
CC       mediates the biosynthesis of cercosporin, a light-activated, non-host-
CC       selective toxin (PubMed:29844193). The perylenequinone chromophore of
CC       cercosporin absorbs light energy to attain an electronically-activated
CC       triplet state and produces active oxygen species such as the hydroxyl
CC       radical, superoxide, hydrogen peroxide or singlet oxygen upon reaction
CC       with oxygen molecules (PubMed:11701851). These reactive oxygen species
CC       cause damage to various cellular components including lipids, proteins
CC       and nucleic acids (PubMed:11701851). The first step of cercosporin
CC       biosynthesis is performed by the polyketide synthase CTB1 which
CC       catalyzes the formation of nor-toralactone (Probable). The starter unit
CC       acyltransferase (SAT) domain of CTB1 initiates polyketide extension by
CC       the selective utilization of acetyl-CoA, which is elongated to the
CC       heptaketide in the beta-ketoacyl synthase (KS) domain by successive
CC       condensations with six malonyl units introduced by the malonyl
CC       acyltransferase (MAT) domain. The product template (PT) domain
CC       catalyzes C4-C9 and C2-C11 aldol cyclizations and dehydrations to a
CC       trihydroxynaphthalene, which is thought to be delivered to the
CC       thioesterase (TE) domain for product release (Probable). The
CC       bifunctional enzyme CTB3 then methylates nor-toralactone to toralactone
CC       before conducting an unusual oxidative aromatic ring opening
CC       (Probable). The O-methyltransferase CTB2 further methylates the nascent
CC       OH-6 of the CBT3 product, blocking further oxidation at this site
CC       before the reductase CTB6 reduces the 2-oxopropyl ketone at position
CC       C7, giving naphthalene (Probable). The FAD-dependent monooxygenase CTB5
CC       in concert with the multicopper oxidase CTB12 are responsible for
CC       homodimerization of naphthalene with CTB7 installing the dioxepine
CC       moiety, finally producing cercosporin (Probable). The fasciclin domain-
CC       containing protein CTB11 might act with CTB5 and CTB12 whereas the
CC       roles of CTB9 and CTB10 have still to be elucidated (By similarity).
CC       {ECO:0000250|UniProtKB:Q0UHZ9, ECO:0000269|PubMed:29844193,
CC       ECO:0000303|PubMed:11701851, ECO:0000305|PubMed:29844193}.
CC   -!- PATHWAY: Mycotoxin biosynthesis. {ECO:0000269|PubMed:29844193}.
CC   -!- DISRUPTION PHENOTYPE: Abolishes the production of cercosporin but
CC       accumulates a red, cercosporin-like metabolite called precercosporin.
CC       {ECO:0000269|PubMed:29844193}.
CC   -!- SIMILARITY: Belongs to the asaB hydroxylase/desaturase family.
CC       {ECO:0000305}.
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DR   EMBL; LKMD01000100; PIB01162.1; -; Genomic_DNA.
DR   AlphaFoldDB; A0A2G5I8W0; -.
DR   SMR; A0A2G5I8W0; -.
DR   OrthoDB; 867824at2759; -.
DR   Proteomes; UP000230605; Chromosome 1.
DR   GO; GO:0016491; F:oxidoreductase activity; IEA:UniProtKB-KW.
DR   InterPro; IPR044053; AsaB-like.
DR   PANTHER; PTHR34598; PTHR34598; 1.
PE   3: Inferred from homology;
KW   Oxidoreductase.
FT   CHAIN           1..324
FT                   /note="Hydroxylase/desaturase CTB9"
FT                   /id="PRO_0000449874"
FT   REGION          1..33
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          288..308
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   324 AA;  37349 MW;  063575DC6B96EFB1 CRC64;
     MTSTITTTET LQDAVPFVAP PSPPEDTSNK ELPEKPYYDV EFNYRLDPRD GGDEVIWGGT
     VGLMRRKYET RTVRINNERG NEHNFNLDTH GFAWVKHKTS VTEFADYLAI RQGPYFGEVA
     EMLKRVTGAT KVHVIGHLHR SLNYNDTTEE EKNAPDMTMT KGQTPGRFVH VDQSYQGAVR
     RLYLDLPQEE ARRLEKTRWA IINVWRPVRK VTNEPLAVCD ARSVREDELF NTLHLVPMRW
     PDAAPQENQM WAVAPPKTPT QHKWHYVSGM TEDEALLIKM FDSKKDGTAR RVPHSSFPTP
     DDFGEPRAST ETRCFVFWED QEAE