AFLX_ASPPU
ID AFLX_ASPPU Reviewed; 266 AA.
AC Q6UEF2; A0A0F0I453;
DT 16-OCT-2013, integrated into UniProtKB/Swiss-Prot.
DT 05-JUL-2004, sequence version 1.
DT 25-MAY-2022, entry version 55.
DE RecName: Full=Oxidoreductase aflX {ECO:0000303|PubMed:16461654};
DE EC=1.-.-.- {ECO:0000305|PubMed:16461654};
DE AltName: Full=Aflatoxin biosynthesis protein X {ECO:0000303|PubMed:15006741};
GN Name=aflX {ECO:0000303|PubMed:15006741};
GN Synonyms=ordB {ECO:0000303|PubMed:15094053}; ORFNames=P875_00053036;
OS Aspergillus parasiticus (strain ATCC 56775 / NRRL 5862 / SRRC 143 / SU-1).
OC Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Eurotiomycetes;
OC Eurotiomycetidae; Eurotiales; Aspergillaceae; Aspergillus.
OX NCBI_TaxID=1403190;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND PATHWAY.
RC STRAIN=ATCC 56775 / NRRL 5862 / SRRC 143 / SU-1;
RX PubMed=15094053; DOI=10.1016/s0014-5793(04)00327-8;
RA Yu J., Bhatnagar D., Cleveland T.E.;
RT "Completed sequence of aflatoxin pathway gene cluster in Aspergillus
RT parasiticus.";
RL FEBS Lett. 564:126-130(2004).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 56775 / NRRL 5862 / SRRC 143 / SU-1;
RA Yu J., Fedorova N., Yin Y., Losada L., Zafar N., Taujale R., Ehrlich K.C.,
RA Bhatnagar D., Cleveland T.E., Bennett J.W., Nierman W.C.;
RT "Draft genome sequence of Aspergillus parasiticus SU-1.";
RL Submitted (FEB-2015) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP FUNCTION.
RX PubMed=1339261; DOI=10.1128/aem.58.11.3527-3537.1992;
RA Skory C.D., Chang P.K., Cary J., Linz J.E.;
RT "Isolation and characterization of a gene from Aspergillus parasiticus
RT associated with the conversion of versicolorin A to sterigmatocystin in
RT aflatoxin biosynthesis.";
RL Appl. Environ. Microbiol. 58:3527-3537(1992).
RN [4]
RP FUNCTION.
RX PubMed=8434913; DOI=10.1128/aem.59.2.479-484.1993;
RA Keller N.P., Dischinger H.C. Jr., Bhatnager D., Cleveland T.E.,
RA Ullah A.H.J.;
RT "Purification of a 40-kilodalton methyltransferase active in the aflatoxin
RT biosynthetic pathway.";
RL Appl. Environ. Microbiol. 59:479-484(1993).
RN [5]
RP FUNCTION.
RX PubMed=8368836; DOI=10.1128/aem.59.8.2486-2492.1993;
RA Yabe K., Matsuyama Y., Ando Y., Nakajima H., Hamasaki T.;
RT "Stereochemistry during aflatoxin biosynthesis: conversion of norsolorinic
RT acid to averufin.";
RL Appl. Environ. Microbiol. 59:2486-2492(1993).
RN [6]
RP FUNCTION.
RX PubMed=8368837; DOI=10.1128/aem.59.8.2493-2500.1993;
RA Yabe K., Hamasaki T.;
RT "Stereochemistry during aflatoxin biosynthesis: cyclase reaction in the
RT conversion of versiconal to versicolorin B and racemization of versiconal
RT hemiacetal acetate.";
RL Appl. Environ. Microbiol. 59:2493-2500(1993).
RN [7]
RP FUNCTION.
RX PubMed=10543813; DOI=10.1128/aem.65.11.4987-4994.1999;
RA Motomura M., Chihaya N., Shinozawa T., Hamasaki T., Yabe K.;
RT "Cloning and characterization of the O-methyltransferase I gene (dmtA) from
RT Aspergillus parasiticus associated with the conversions of
RT demethylsterigmatocystin to sterigmatocystin and
RT dihydrodemethylsterigmatocystin to dihydrosterigmatocystin in aflatoxin
RT biosynthesis.";
RL Appl. Environ. Microbiol. 65:4987-4994(1999).
RN [8]
RP FUNCTION.
RX PubMed=10584035; DOI=10.1128/aem.65.12.5639-5641.1999;
RA Zhou R., Linz J.E.;
RT "Enzymatic function of the nor-1 protein in aflatoxin biosynthesis in
RT Aspergillus parasiticus.";
RL Appl. Environ. Microbiol. 65:5639-5641(1999).
RN [9]
RP FUNCTION.
RX PubMed=11055914; DOI=10.1128/aem.66.11.4715-4719.2000;
RA Chang P.K., Yu J., Ehrlich K.C., Boue S.M., Montalbano B.G., Bhatnagar D.,
RA Cleveland T.E.;
RT "adhA in Aspergillus parasiticus is involved in conversion of 5'-
RT hydroxyaverantin to averufin.";
RL Appl. Environ. Microbiol. 66:4715-4719(2000).
RN [10]
RP FUNCTION.
RX PubMed=16256699; DOI=10.1006/bioo.2001.1216;
RA Hitchman T.S., Schmidt E.W., Trail F., Rarick M.D., Linz J.E.,
RA Townsend C.A.;
RT "Hexanoate synthase, a specialized type I fatty acid synthase in aflatoxin
RT B1 biosynthesis.";
RL Bioorg. Chem. 29:293-307(2001).
RN [11]
RP FUNCTION.
RX PubMed=11996570; DOI=10.1021/ja012185v;
RA Udwary D.W., Casillas L.K., Townsend C.A.;
RT "Synthesis of 11-hydroxyl O-methylsterigmatocystin and the role of a
RT cytochrome P-450 in the final step of aflatoxin biosynthesis.";
RL J. Am. Chem. Soc. 124:5294-5303(2002).
RN [12]
RP REVIEW, FUNCTION, PATHWAY, AND NOMENCLATURE.
RX PubMed=15006741; DOI=10.1128/aem.70.3.1253-1262.2004;
RA Yu J., Chang P.K., Ehrlich K.C., Cary J.W., Bhatnagar D., Cleveland T.E.,
RA Payne G.A., Linz J.E., Woloshuk C.P., Bennett J.W.;
RT "Clustered pathway genes in aflatoxin biosynthesis.";
RL Appl. Environ. Microbiol. 70:1253-1262(2004).
RN [13]
RP FUNCTION.
RX PubMed=15528514; DOI=10.1128/aem.70.11.6518-6524.2004;
RA Ehrlich K.C., Chang P.K., Yu J., Cotty P.J.;
RT "Aflatoxin biosynthesis cluster gene cypA is required for G aflatoxin
RT formation.";
RL Appl. Environ. Microbiol. 70:6518-6524(2004).
RN [14]
RP FUNCTION.
RX PubMed=15932995; DOI=10.1128/aem.71.6.2999-3006.2005;
RA Sakuno E., Wen Y., Hatabayashi H., Arai H., Aoki C., Yabe K., Nakajima H.;
RT "Aspergillus parasiticus cyclase catalyzes two dehydration steps in
RT aflatoxin biosynthesis.";
RL Appl. Environ. Microbiol. 71:2999-3006(2005).
RN [15]
RP FUNCTION.
RX PubMed=16332900; DOI=10.1128/aem.71.12.8963-8965.2005;
RA Ehrlich K.C., Montalbano B., Boue S.M., Bhatnagar D.;
RT "An aflatoxin biosynthesis cluster gene encodes a novel oxidase required
RT for conversion of versicolorin a to sterigmatocystin.";
RL Appl. Environ. Microbiol. 71:8963-8965(2005).
RN [16]
RP FUNCTION.
RX PubMed=15771506; DOI=10.1021/ja0455188;
RA Henry K.M., Townsend C.A.;
RT "Ordering the reductive and cytochrome P450 oxidative steps in
RT demethylsterigmatocystin formation yields general insights into the
RT biosynthesis of aflatoxin and related fungal metabolites.";
RL J. Am. Chem. Soc. 127:3724-3733(2005).
RN [17]
RP FUNCTION.
RC STRAIN=ATCC 56775 / NRRL 5862 / SRRC 143 / SU-1;
RX PubMed=16461654; DOI=10.1128/aem.72.2.1096-1101.2006;
RA Cary J.W., Ehrlich K.C., Bland J.M., Montalbano B.G.;
RT "The aflatoxin biosynthesis cluster gene, aflX, encodes an oxidoreductase
RT involved in conversion of versicolorin A to demethylsterigmatocystin.";
RL Appl. Environ. Microbiol. 72:1096-1101(2006).
RN [18]
RP FUNCTION.
RX PubMed=18486503; DOI=10.1016/j.fgb.2008.03.003;
RA Cai J., Zeng H., Shima Y., Hatabayashi H., Nakagawa H., Ito Y., Adachi Y.,
RA Nakajima H., Yabe K.;
RT "Involvement of the nadA gene in formation of G-group aflatoxins in
RT Aspergillus parasiticus.";
RL Fungal Genet. Biol. 45:1081-1093(2008).
RN [19]
RP FUNCTION.
RX PubMed=18403714; DOI=10.1126/science.1154711;
RA Crawford J.M., Thomas P.M., Scheerer J.R., Vagstad A.L., Kelleher N.L.,
RA Townsend C.A.;
RT "Deconstruction of iterative multidomain polyketide synthase function.";
RL Science 320:243-246(2008).
CC -!- FUNCTION: Oxidoreductase; part of the gene cluster that mediates the
CC biosynthesis of aflatoxins, a group of polyketide-derived
CC furanocoumarins, and part of the most toxic and carcinogenic compounds
CC among the known mycotoxins (PubMed:15006741). The four major aflatoxins
CC produced by A.parasiticus are aflatoxin B1 (AFB1), aflatoxin B2 (AFB2),
CC aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2) (PubMed:15006741). The
CC first step of the pathway is the conversion of acetate to norsolorinic
CC acid (NOR) and requires the fatty acid synthase subunits aflA and aflB,
CC as well as the PKS aflC (PubMed:15006741). AflC combines a hexanoyl
CC starter unit and 7 malonyl-CoA extender units to synthesize the
CC precursor NOR (PubMed:18403714). The hexanoyl starter unit is provided
CC to the acyl-carrier protein (ACP) domain by the fungal fatty acid
CC synthase aflA/aflB (PubMed:16256699). The second step is the conversion
CC of NOR to averantin (AVN) and requires the norsolorinic acid
CC ketoreductase aflD, which catalyzes the dehydration of norsolorinic
CC acid to form (1'S)-averantin (PubMed:10584035). The norsolorinic acid
CC reductases aflE and aflF may also play a role in the conversion of NOR
CC to AVN (PubMed:15006741). The cytochrome P450 monooxygenase aflG then
CC catalyzes the hydroxylation of AVN to 5'hydroxyaverantin (HAVN)
CC (PubMed:8368836). The next step is performed by the 5'-hydroxyaverantin
CC dehydrogenase aflH that transforms HAVN to 5'-oxoaverantin (OAVN) which
CC is further converted to averufin (AVF) by aflK that plays a dual role
CC in the pathway, as a 5'-oxoaverantin cyclase that mediates conversion
CC of 5'-oxoaverantin, as well as a versicolorin B synthase in a later
CC step in the pathway (PubMed:15006741, PubMed:11055914,
CC PubMed:15932995). The averufin oxidase aflI catalyzes the conversion of
CC AVF to versiconal hemiacetal acetate (VHA) (PubMed:15006741). VHA is
CC then the substrate for the versiconal hemiacetal acetate esterase aflJ
CC to yield versiconal (VAL) (PubMed:15006741). Versicolorin B synthase
CC aflK then converts VAL to versicolorin B (VERB) by closing the bisfuran
CC ring of aflatoxin which is required for DNA-binding, thus giving to
CC aflatoxin its activity as a mutagen (PubMed:15006741, PubMed:8368837,
CC PubMed:15932995). Then, the activity of the versicolorin B desaturase
CC aflL leads to versicolorin A (VERA) (PubMed:15006741, PubMed:8368837).
CC A branch point starts from VERB since it can also be converted to
CC dihydrodemethylsterigmatocystin (DMDHST), probably also by aflL, VERA
CC being a precursor for aflatoxins B1 and G1, and DMDHST for aflatoxins
CC B2 and G2 (PubMed:15006741). Next, the versicolorin reductase aflM and
CC the cytochrome P450 monooxygenase aflN are involved in conversion of
CC VERA to demethylsterigmatocystin (DMST) (PubMed:15006741,
CC PubMed:1339261, PubMed:15771506). AflX and aflY seem also involved in
CC this step, through probable aflX-mediated epoxide ring-opening step
CC following versicolorin A oxidation and aflY-mediated Baeyer-Villiger
CC oxidation required for the formation of the xanthone ring
CC (PubMed:16332900, PubMed:16461654). The methyltransferase aflO then
CC leads to the modification of DMST to sterigmatocystin (ST), and of
CC DMDHST to dihydrosterigmatocystin (DHST) (PubMed:10543813). Both ST and
CC DHST are then substrates of the O-methyltransferase aflP to yield O-
CC methylsterigmatocystin (OMST) and dihydro-O-methylsterigmatocystin
CC (DHOMST), respectively (PubMed:8434913). Finally OMST is converted to
CC aflatoxins B1 and G1, and DHOMST to aflatoxins B2 and G2, via the
CC action of several enzymes including O-methylsterigmatocystin
CC oxidoreductase aflQ, the cytochrome P450 monooxygenase aflU, but also
CC the NADH-dependent flavin oxidoreductase nadA which is specifically
CC required for the synthesis of AFG1 (PubMed:15006741, PubMed:11996570,
CC PubMed:15528514, PubMed:18486503). {ECO:0000269|PubMed:10543813,
CC ECO:0000269|PubMed:10584035, ECO:0000269|PubMed:11055914,
CC ECO:0000269|PubMed:11996570, ECO:0000269|PubMed:1339261,
CC ECO:0000269|PubMed:15528514, ECO:0000269|PubMed:15771506,
CC ECO:0000269|PubMed:15932995, ECO:0000269|PubMed:16256699,
CC ECO:0000269|PubMed:16332900, ECO:0000269|PubMed:16461654,
CC ECO:0000269|PubMed:18403714, ECO:0000269|PubMed:18486503,
CC ECO:0000269|PubMed:8368836, ECO:0000269|PubMed:8368837,
CC ECO:0000269|PubMed:8434913, ECO:0000305|PubMed:15006741}.
CC -!- PATHWAY: Mycotoxin biosynthesis; aflatoxin biosynthesis.
CC {ECO:0000269|PubMed:15094053, ECO:0000305|PubMed:15006741}.
CC -!- SIMILARITY: Belongs to the avfA family. {ECO:0000305}.
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DR EMBL; AY371490; AAS66024.1; -; Genomic_DNA.
DR EMBL; JZEE01000729; KJK60763.1; -; Genomic_DNA.
DR AlphaFoldDB; Q6UEF2; -.
DR EnsemblFungi; KJK60763; KJK60763; P875_00053036.
DR UniPathway; UPA00287; -.
DR Proteomes; UP000033540; Unassembled WGS sequence.
DR GO; GO:0004497; F:monooxygenase activity; IDA:UniProtKB.
DR GO; GO:0045122; P:aflatoxin biosynthetic process; IDA:UniProtKB.
DR InterPro; IPR016040; NAD(P)-bd_dom.
DR InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR Pfam; PF13460; NAD_binding_10; 1.
DR SUPFAM; SSF51735; SSF51735; 1.
PE 3: Inferred from homology;
KW Monooxygenase; Oxidoreductase; Reference proteome.
FT CHAIN 1..266
FT /note="Oxidoreductase aflX"
FT /id="PRO_0000424168"
SQ SEQUENCE 266 AA; 29374 MW; 3C1995C24B7EC615 CRC64;
MRRYAILGAT GNTGQALLNV LLQSPDNQIH AYCRSASKLN RLRPEISQHR QVKVWEGSLE
DVSLLSECIR GTRAVFMVVA IPDNMPHCTI AQDCTNAVLN TLKKLQAEGC QSLPKLIVLS
SASLEDSLCA DVPPLIHRVL NIAAGNLYSD LAKAEKILRA EKHWVSTTFV KPGGLVHDVQ
RGHTLSTKTA KTPVSFLDVA AGMVEIADMD DKTYDMMNVS VNAIGDGTAF PWKGVYYVLT
GLLFHFFPWT YKYFGDSPMP KPRKDL
