AFLL_ASPPU
ID AFLL_ASPPU Reviewed; 500 AA.
AC Q9UW95; A0A0F0I0Q6;
DT 16-OCT-2013, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-2000, sequence version 1.
DT 03-AUG-2022, entry version 89.
DE RecName: Full=Versicolorin B desaturase {ECO:0000303|PubMed:8368837};
DE EC=1.14.19.n5 {ECO:0000269|PubMed:1339261};
DE AltName: Full=Aflatoxin biosynthesis protein L {ECO:0000303|PubMed:15006741};
GN Name=aflL {ECO:0000303|PubMed:15006741}; Synonyms=verB;
GN ORFNames=P875_00052996-1;
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 [GENOMIC DNA].
RC STRAIN=RH1;
RA Bhatnagar D., Cary J.W., Ehrlich K.C., Cleveland T.E., Payne G.A.;
RT "Molecular characterization of an aflatoxin B2 producing mutant strain of
RT Aspergillus flavus.";
RL Submitted (NOV-1998) to the EMBL/GenBank/DDBJ databases.
RN [3]
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 [4]
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 [5]
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 [6]
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 [7]
RP FUNCTION, CATALYTIC ACTIVITY, AND PATHWAY.
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 [8]
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 [9]
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 [10]
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 [11]
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 [12]
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 [13]
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 [14]
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 [15]
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 [16]
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 [17]
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 [18]
RP FUNCTION.
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 [19]
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 [20]
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: Fatty acid synthase alpha subunit; part of the gene cluster
CC that mediates the biosynthesis of aflatoxins, a group of polyketide-
CC derived furanocoumarins, and part of the most toxic and carcinogenic
CC compounds among the known mycotoxins (PubMed:15006741). The four major
CC aflatoxins produced by A.parasiticus are aflatoxin B1 (AFB1), aflatoxin
CC B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2)
CC (PubMed:15006741). The first step of the pathway is the conversion of
CC acetate to norsolorinic acid (NOR) and requires the fatty acid synthase
CC subunits aflA and aflB, as well as the PKS aflC (PubMed:15006741). AflC
CC combines a hexanoyl starter unit and 7 malonyl-CoA extender units to
CC synthesize the precursor NOR (PubMed:18403714). The hexanoyl starter
CC unit is provided to the acyl-carrier protein (ACP) domain by the fungal
CC fatty acid synthase aflA/aflB (PubMed:16256699). The second step is the
CC conversion 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 -!- CATALYTIC ACTIVITY:
CC Reaction=H(+) + NADPH + O2 + versicolorin B = 2 H2O + NADP(+) +
CC versicolorin A; Xref=Rhea:RHEA:35743, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:15379, ChEBI:CHEBI:57783,
CC ChEBI:CHEBI:58349, ChEBI:CHEBI:77951, ChEBI:CHEBI:77976;
CC EC=1.14.19.n5; Evidence={ECO:0000269|PubMed:8368837};
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000250|UniProtKB:P04798};
CC -!- PATHWAY: Mycotoxin biosynthesis; aflatoxin biosynthesis.
CC {ECO:0000269|PubMed:15094053, ECO:0000269|PubMed:8368837,
CC ECO:0000305|PubMed:15006741}.
CC -!- SUBCELLULAR LOCATION: Membrane {ECO:0000255}; Single-pass membrane
CC protein {ECO:0000255}.
CC -!- SIMILARITY: Belongs to the cytochrome P450 family. {ECO:0000305}.
CC -!- SEQUENCE CAUTION:
CC Sequence=KJK60771.1; Type=Erroneous gene model prediction; Note=The predicted gene P875_00052996 has been split into 2 genes: P875_00052996-1 (aflL) and P875_00052996-2 (aflG).; Evidence={ECO:0000305};
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DR EMBL; AY371490; AAS66013.1; -; Genomic_DNA.
DR EMBL; AF106958; AAD50366.1; -; Genomic_DNA.
DR EMBL; JZEE01000729; KJK60771.1; ALT_SEQ; Genomic_DNA.
DR AlphaFoldDB; Q9UW95; -.
DR SMR; Q9UW95; -.
DR BioCyc; MetaCyc:MON-14041; -.
DR UniPathway; UPA00287; -.
DR Proteomes; UP000033540; Unassembled WGS sequence.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0020037; F:heme binding; IEA:InterPro.
DR GO; GO:0005506; F:iron ion binding; IEA:InterPro.
DR GO; GO:0004497; F:monooxygenase activity; IEA:UniProtKB-KW.
DR GO; GO:0140398; F:versicolorin B desaturase activity; IEA:RHEA.
DR GO; GO:0045122; P:aflatoxin biosynthetic process; IMP:GO_Central.
DR Gene3D; 1.10.630.10; -; 1.
DR InterPro; IPR001128; Cyt_P450.
DR InterPro; IPR017972; Cyt_P450_CS.
DR InterPro; IPR002401; Cyt_P450_E_grp-I.
DR InterPro; IPR036396; Cyt_P450_sf.
DR Pfam; PF00067; p450; 1.
DR PRINTS; PR00463; EP450I.
DR PRINTS; PR00385; P450.
DR SUPFAM; SSF48264; SSF48264; 1.
DR PROSITE; PS00086; CYTOCHROME_P450; 1.
PE 1: Evidence at protein level;
KW Glycoprotein; Heme; Iron; Membrane; Metal-binding; Monooxygenase; NADP;
KW Oxidoreductase; Reference proteome; Transmembrane; Transmembrane helix.
FT CHAIN 1..500
FT /note="Versicolorin B desaturase"
FT /id="PRO_0000424166"
FT TRANSMEM 3..23
FT /note="Helical"
FT /evidence="ECO:0000255"
FT BINDING 438
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P04798"
FT CARBOHYD 243
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
FT CARBOHYD 400
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
SQ SEQUENCE 500 AA; 56554 MW; BDB5860D137A68A4 CRC64;
MYFLSLPSLV IVIPVGYLLF HLGYNLFFHP LRGYPGPLLW RASSLPWKIA LLRGTMHHDL
MRFHQKYGDT VRIKPDEISY ANAQAWRDIH AHVPGRPEFL KDPVRLPLAP NGVMSILVSD
TKNHARFRSL FGHAFSDKGL RTQESTIVQY ADLLVEVLRE VADTGRSAEM VYYFNMAIFD
SIGALSFGES FDSLKSRQLH PWVDAIHKNL KSVAISHVLR SMGIEFLTPY VLPKELRGKR
QENYSYAVEK LNKRMKMEGD QGDFWDKVLV KSADDNQRGD GMSAGEMLNN AAVMVVAGSE
TTASALSGAM YLLCLSGKIE KATAEIRKSF ASPEDIDLIS VSHLPYLTAV IDETLRMYPA
VPGQPPRVVP ASGATVCGRF VPEETRVGVS HLATYFADYN FTHADKFIPE RHLQKTEEPF
KYDNYGAYQP WSVGLRNCIG RNLAYAEVRL TLAKLLWHFD FTLDVDKTGN FLDQKIWSIW
AKRELYMFIK TRGTSSSSPQ
