ID   TAS3_HAPIR              Reviewed;         397 AA.
AC   A0A0F7GGT4;
DT   29-SEP-2021, integrated into UniProtKB/Swiss-Prot.
DT   22-JUL-2015, sequence version 1.
DT   03-AUG-2022, entry version 6.
DE   RecName: Full=Diels-Alderase tas3 {ECO:0000303|PubMed:25885659};
DE            EC=5.5.1.- {ECO:0000305|PubMed:25885659};
DE   AltName: Full=Tetramic acid Sch210971/2 biosynthesis cluster protein 3 {ECO:0000303|PubMed:25885659};
GN   Name=tas3 {ECO:0000303|PubMed:25885659};
OS   Hapsidospora irregularis.
OC   Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Sordariomycetes;
OC   Hypocreomycetidae; Hypocreales; Hypocreales incertae sedis; Hapsidospora.
OX   NCBI_TaxID=95324;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY, AND
RP   PATHWAY.
RX   PubMed=25885659; DOI=10.1021/acs.orglett.5b00715;
RA   Kakule T.B., Zhang S., Zhan J., Schmidt E.W.;
RT   "Biosynthesis of the tetramic acids Sch210971 and Sch210972.";
RL   Org. Lett. 17:2295-2297(2015).
CC   -!- FUNCTION: Diels-Alderase; part of the gene cluster that mediates the
CC       biosynthesis of the tetramic acids Sch210971 and Sch210972, potential
CC       anti-HIV fungal natural product that contain a decalin core
CC       (PubMed:25885659). The PKS module of tasS together with the
CC       enoylreductase tasC catalyze the formation of the polyketide unit which
CC       is then conjugated to 4-hydroxyl-4-methyl glutamate (HMG) by the
CC       condensation domain of the tasS NRPS module (PubMed:25885659). One
CC       unique structural feature of Sch210971 and Sch210972 is the tetramic
CC       acid motif proposed to be derived from the non-proteinogenic amino acid
CC       HMG, by a Dieckmann-type condensation catalyzed by the reductase domain
CC       of tasS (PubMed:25885659). The aldolase tasA catalyzes the aldol
CC       condensation of 2 molecules of pyruvic acid to yield the intermediate
CC       4-hydroxyl-4-methyl-2-oxoglutarate (HMOG), which can then be
CC       stereoselectively transaminated, may be by tasG, to form HMG
CC       (PubMed:25885659). The Diels-Alderase tas3 then uses the Dieckmann
CC       product of tasS as substrate and catalyzes the Diels-Alder
CC       cycloaddition to form the decalin ring of Sch210971 and Sch210972
CC       (PubMed:25885659). {ECO:0000269|PubMed:25885659}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(2S)-3-[(2S)-3,5-dioxo-4-[(2E,4R,6R,8E,10E,12E)-4,6,12-
CC         trimethyltetradeca-2,8,10,12-tetraenoyl]pyrrolidin-2-yl]-2-hydroxy-2-
CC         methylpropanoate = sch 210972; Xref=Rhea:RHEA:67268,
CC         ChEBI:CHEBI:167897, ChEBI:CHEBI:167907;
CC         Evidence={ECO:0000269|PubMed:25885659};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:67269;
CC         Evidence={ECO:0000269|PubMed:25885659};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(2R)-3-[(2S)-3,5-dioxo-4-[(2E,4R,6R,8E,10E,12E)-4,6,12-
CC         trimethyltetradeca-2,8,10,12-tetraenoyl]pyrrolidin-2-yl]-2-hydroxy-2-
CC         methylpropanoate = sch 210971; Xref=Rhea:RHEA:67320,
CC         ChEBI:CHEBI:167911, ChEBI:CHEBI:167912;
CC         Evidence={ECO:0000269|PubMed:25885659};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:67321;
CC         Evidence={ECO:0000269|PubMed:25885659};
CC   -!- PATHWAY: Secondary metabolite biosynthesis.
CC       {ECO:0000269|PubMed:25885659}.
CC   -!- SIMILARITY: Belongs to the Diels-Alderase family. {ECO:0000305}.
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DR   EMBL; KP835202; AKG54860.1; -; Genomic_DNA.
DR   SMR; A0A0F7GGT4; -.
DR   GO; GO:0016853; F:isomerase activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Isomerase.
FT   CHAIN           1..397
FT                   /note="Diels-Alderase tas3"
FT                   /id="PRO_0000453340"
SQ   SEQUENCE   397 AA;  42581 MW;  5B20B02642AA870F CRC64;
     MVDIFTSEFT VGESITTDPI PESDFIPNSG NLFPKFPDQI RKTAVEVWLF DAIAEDGSSA
     ITISFFRDAL AAPAGFRIAV NASWSDGTIW GKPLIFPKSL ITSKGPDVGS GAVTGVWRTD
     EDSSSHATFE VAADLSTAKV TFDVPGKVVG TLELKSLGFH PLPRSAREAE AAPSIYWMRS
     IAKAAATVDM VFTSPSADGE STTERPLVIG KDENPAFGGV DRSWESVGWT QAVTDSVFLR
     AKSGPYDLHF MLLVGKAEQD YRLTASASLY RDGELVCAPH DVLHHTEDGI TTGAAAATTT
     TTRGDVDTLV VKKLFEGEGL PAPFRHQNVG YQLEYTSGGP DGKTWVFETR HQRAWYRKPT
     GPGTGSSGFI VSVTGGEAGK GKSFQGWGYE GQVVLPE