ID AFLP_ASPPU Reviewed; 418 AA.
AC Q12120; A0A0F0HZ60;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1997, sequence version 1.
DT 27-MAR-2024, entry version 90.
DE RecName: Full=Sterigmatocystin 8-O-methyltransferase {ECO:0000303|PubMed:8434913};
DE EC=2.1.1.110 {ECO:0000269|PubMed:8434913};
DE AltName: Full=Aflatoxin biosynthesis protein P {ECO:0000303|PubMed:15006741};
DE Flags: Precursor;
GN Name=aflP {ECO:0000303|PubMed:15006741}; Synonyms=omt-1, omtA;
GN ORFNames=P875_00052999-1;
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 [MRNA].
RC STRAIN=ATCC 56775 / NRRL 5862 / SRRC 143 / SU-1;
RX PubMed=8285664; DOI=10.1128/aem.59.11.3564-3571.1993;
RA Yu J., Cary J.W., Bhatnager D., Cleveland T.E., Keller N.P., Chu F.S.;
RT "Cloning and characterization of a cDNA from Aspergillus parasiticus
RT encoding an O-methyltransferase involved in aflatoxin biosynthesis.";
RL Appl. Environ. Microbiol. 59:3564-3571(1993).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=70;
RA Yu J.;
RL Submitted (NOV-1993) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 56775 / NRRL 5862 / SRRC 143 / SU-1;
RX PubMed=7557460; DOI=10.1016/0378-1119(95)00397-o;
RA Yu J., Chang P.-K., Payne G.A., Cary J.W., Bhatnagar D., Cleveland T.E.;
RT "Comparison of the omtA genes encoding O-methyltransferases involved in
RT aflatoxin biosynthesis from Aspergillus parasiticus and A. flavus.";
RL Gene 163:121-125(1995).
RN [4]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
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 [5]
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 [6]
RP PROTEIN SEQUENCE OF 42-63, FUNCTION, CATALYTIC ACTIVITY, AND
RP BIOPHYSICOCHEMICAL PROPERTIES.
RC STRAIN=ATCC 56774 / SRRC 163 / avn-1;
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 [7]
RP 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 [8]
RP SUBCELLULAR LOCATION.
RX PubMed=14722624; DOI=10.1007/s00203-003-0643-3;
RA Lee L.W., Chiou C.H., Klomparens K.L., Cary J.W., Linz J.E.;
RT "Subcellular localization of aflatoxin biosynthetic enzymes Nor-1, Ver-1,
RT and OmtA in time-dependent fractionated colonies of Aspergillus
RT parasiticus.";
RL Arch. Microbiol. 181:204-214(2004).
RN [9]
RP INDUCTION.
RX PubMed=23113196;
RA Jahanshiri Z., Shams-Ghahfarokhi M., Allameh A., Razzaghi-Abyaneh M.;
RT "Effect of curcumin on Aspergillus parasiticus growth and expression of
RT major genes involved in the early and late stages of aflatoxin
RT biosynthesis.";
RL Iran. J. Public Health 41:72-79(2012).
RN [10]
RP INDUCTION.
RX PubMed=24294264; DOI=10.1590/s1517-83822013000200045;
RA Yahyaraeyat R., Khosravi A.R., Shahbazzadeh D., Khalaj V.;
RT "The potential effects of Zataria multiflora Boiss essential oil on growth,
RT aflatoxin production and transcription of aflatoxin biosynthesis pathway
RT genes of toxigenic Aspergillus parasiticus.";
RL Braz. J. Microbiol. 44:643-649(2013).
CC -!- FUNCTION: Sterigmatocystin 8-O-methyltransferase; part of the gene
CC cluster that mediates the biosynthesis of aflatoxins, a group of
CC polyketide-derived furanocoumarins, and part of the most toxic and
CC carcinogenic compounds among the known mycotoxins (PubMed:8434913,
CC PubMed:15006741). The four major aflatoxins produced by A.parasiticus
CC are aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and
CC aflatoxin G2 (AFG2) (PubMed:15006741). Within the aflatoxin pathway,
CC the O-methyltransferase aflP uses both sterigmatocystin (ST) and
CC dihydrosterigmatocystin (DHST) as substrates to yield O-
CC methylsterigmatocystin (OMST) and dihydro-O-methylsterigmatocystin
CC (DHOMST), respectively (PubMed:8434913). The biosynthesis of aflatoxins
CC begins with the norsolorinic acid synthase aflC that combines a
CC hexanoyl starter unit produced by the fatty acid synthase aflA/aflB and
CC 7 malonyl-CoA extender units to synthesize the precursor NOR. The
CC second step is the conversion of NOR to averantin and requires the
CC norsolorinic acid ketoreductase aflD, which catalyzes the dehydration
CC of norsolorinic acid to form (1'S)-averantin. The norsolorinic acid
CC reductases aflE and aflF may also play a role in the conversion of NOR
CC to AVN. The cytochrome P450 monooxygenase aflG then catalyzes the
CC hydroxylation of AVN to 5'hydroxyaverantin (HAVN). The next step is
CC performed by the 5'-hydroxyaverantin dehydrogenase aflH that transforms
CC HAVN to 5'-oxoaverantin (OAVN) which is further converted to averufin
CC (AVF) by aflK that plays a dual role in the pathway, as a 5'-
CC oxoaverantin cyclase that mediates conversion of 5'-oxoaverantin, as
CC well as a versicolorin B synthase in a later step in the pathway. The
CC averufin oxidase aflI catalyzes the conversion of AVF to versiconal
CC hemiacetal acetate (VHA). VHA is then the substrate for the versiconal
CC hemiacetal acetate esterase aflJ to yield versiconal (VAL).
CC Versicolorin B synthase aflK then converts VAL to versicolorin B (VERB)
CC by closing the bisfuran ring of aflatoxin which is required for DNA-
CC binding, thus giving to aflatoxin its activity as a mutagen. Then, the
CC activity of the versicolorin B desaturase aflL leads to versicolorin A
CC (VERA). A branch point starts from VERB since it can also be converted
CC to dihydrodemethylsterigmatocystin (DMDHST), probably also by aflL,
CC VERA being a precursor for aflatoxins B1 and G1, and DMDHST for
CC aflatoxins B2 and G2. Next, the versicolorin reductase aflM and the
CC cytochrome P450 monooxygenase aflN are involved in conversion of VERA
CC to demethylsterigmatocystin (DMST). 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. The
CC methyltransferase aflO then leads to the modification of DMST to
CC sterigmatocystin (ST), and of DMDHST to dihydrosterigmatocystin (DHST).
CC Both ST and DHST are then substrates of the O-methyltransferase aflP to
CC yield O-methylsterigmatocystin (OMST) and dihydro-O-
CC methylsterigmatocystin (DHOMST), respectively. Finally OMST is
CC converted to aflatoxins B1 and G1, and DHOMST to aflatoxins B2 and G2,
CC via the 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).
CC {ECO:0000269|PubMed:8434913, ECO:0000305|PubMed:15006741}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=S-adenosyl-L-methionine + sterigmatocystin = 8-O-
CC methylsterigmatocystin + H(+) + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:15561, ChEBI:CHEBI:15378, ChEBI:CHEBI:18171,
CC ChEBI:CHEBI:18227, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789;
CC EC=2.1.1.110; Evidence={ECO:0000269|PubMed:8434913};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:15562;
CC Evidence={ECO:0000269|PubMed:8434913};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=dihydrosterigmatocystin + S-adenosyl-L-methionine = 8-O-
CC methyldihydrosterigmatocystin + H(+) + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:35767, ChEBI:CHEBI:15378, ChEBI:CHEBI:57856,
CC ChEBI:CHEBI:59789, ChEBI:CHEBI:72677, ChEBI:CHEBI:72678;
CC EC=2.1.1.110; Evidence={ECO:0000269|PubMed:8434913};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:35768;
CC Evidence={ECO:0000269|PubMed:8434913};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=2 uM for sterigmatocystin {ECO:0000269|PubMed:8434913};
CC KM=9.6 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:8434913};
CC pH dependence:
CC Optimum pH is 7-9.4. {ECO:0000269|PubMed:8434913};
CC Temperature dependence:
CC Optimum temperature is 40-45 degrees Celsius.
CC {ECO:0000269|PubMed:8434913};
CC -!- PATHWAY: Mycotoxin biosynthesis; aflatoxin biosynthesis.
CC {ECO:0000305|PubMed:15006741}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:14722624}. Vacuole
CC {ECO:0000269|PubMed:14722624}.
CC -!- INDUCTION: Zataria multiflora essential oil reduces gene expression
CC (PubMed:24294264). Expression is repressed by curcumin
CC (PubMed:23113196). {ECO:0000269|PubMed:23113196,
CC ECO:0000269|PubMed:24294264}.
CC -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC superfamily. Cation-independent O-methyltransferase family. COMT
CC subfamily. {ECO:0000255|PROSITE-ProRule:PRU01020}.
CC -!- SEQUENCE CAUTION:
CC Sequence=KJK60770.1; Type=Erroneous gene model prediction; Note=The predicted gene P875_00052999 has been split into 2 genes: P875_00052999-1 (aflP) and P875_00052999-2 (aflO).; Evidence={ECO:0000305};
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DR EMBL; L22091; AAA32697.1; -; mRNA.
DR EMBL; L25835; AAA32699.1; -; Genomic_DNA.
DR EMBL; AY371490; AAS66017.1; -; Genomic_DNA.
DR EMBL; JZEE01000729; KJK60770.1; ALT_SEQ; Genomic_DNA.
DR AlphaFoldDB; Q12120; -.
DR SMR; Q12120; -.
DR STRING; 1403190.Q12120; -.
DR KEGG; ag:AAA32697; -.
DR BioCyc; MetaCyc:MONOMER-14043; -.
DR UniPathway; UPA00287; -.
DR Proteomes; UP000033540; Unassembled WGS sequence.
DR GO; GO:0005829; C:cytosol; IDA:UniProt.
DR GO; GO:0005773; C:vacuole; IEA:UniProtKB-SubCell.
DR GO; GO:0008171; F:O-methyltransferase activity; IDA:UniProt.
DR GO; GO:0047146; F:sterigmatocystin 7-O-methyltransferase activity; IDA:UniProt.
DR GO; GO:0045122; P:aflatoxin biosynthetic process; IDA:GO_Central.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR Gene3D; 3.40.50.150; Vaccinia Virus protein VP39; 1.
DR Gene3D; 1.10.10.10; Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain; 1.
DR InterPro; IPR016461; COMT-like.
DR InterPro; IPR001077; O_MeTrfase_dom.
DR InterPro; IPR029063; SAM-dependent_MTases_sf.
DR InterPro; IPR036388; WH-like_DNA-bd_sf.
DR InterPro; IPR036390; WH_DNA-bd_sf.
DR PANTHER; PTHR43712:SF20; O-METHYLTRANSFERASE ASQN; 1.
DR PANTHER; PTHR43712; PUTATIVE (AFU_ORTHOLOGUE AFUA_4G14580)-RELATED; 1.
DR Pfam; PF00891; Methyltransf_2; 1.
DR SUPFAM; SSF53335; S-adenosyl-L-methionine-dependent methyltransferases; 1.
DR SUPFAM; SSF46785; Winged helix' DNA-binding domain; 1.
DR PROSITE; PS51683; SAM_OMT_II; 1.
PE 1: Evidence at protein level;
KW Cytoplasm; Direct protein sequencing; Methyltransferase;
KW Reference proteome; S-adenosyl-L-methionine; Transferase; Vacuole; Zymogen.
FT PROPEP 1..41
FT /evidence="ECO:0000269|PubMed:8434913"
FT /id="PRO_0000021898"
FT CHAIN 42..418
FT /note="Sterigmatocystin 8-O-methyltransferase"
FT /id="PRO_0000021899"
FT REGION 206..225
FT /note="Substrate binding"
FT /evidence="ECO:0000250"
FT ACT_SITE 317
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT BINDING 170..176
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT BINDING 254..255
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:O04385"
FT BINDING 277
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:O04385"
FT BINDING 297..298
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:O04385"
FT BINDING 313
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:O04385"
FT CONFLICT 48
FT /note="S -> D (in Ref. 6; AA sequence)"
FT /evidence="ECO:0000305"
FT CONFLICT 61
FT /note="C -> Q (in Ref. 6; AA sequence)"
FT /evidence="ECO:0000305"
FT CONFLICT 63
FT /note="R -> P (in Ref. 6; AA sequence)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 418 AA; 46397 MW; 2CC5F93245F91262 CRC64;
MALPSKAALV GLANTLSEQV KRYLATAGET KSPEDHKLCI ESERTPSSNE HAQAWEIVRT
CDRIGSLVHG PVPWLLSNAL SHLDSACLAA ATHLNLQDII VDGPSPTSLD TIVAATGVSE
DLLRRILRGC AQRFIFEEVA PDQYAHTDAS KMLRVTGIHA LVGFSCDEVM RSGASFSDFL
QQTKGKPPSW NVPSPFSLAF DPTKGLFDYY STVDEVRGRR FDLGMGGTEA TKPLVEEMFD
FSSLPEGSTV VDVGGGRGHL SRRVSQKHPH LRFIVQDLPA VIHGVEDTDK VTMMEHDIRR
PNPVRGADVY LLRSILHDYP DAACVEILSN IVTAMDPSKS RILLDEMIMP DLLAQDSQRF
MNQIDMTVVL TLNGKERSTK EWNSLITTVD GRLETEKIWW RKGEEGSHWG VQQLRLRK
//
