ID   STS18_POSPM             Reviewed;         348 AA.
AC   A0A348B790;
DT   02-DEC-2020, integrated into UniProtKB/Swiss-Prot.
DT   07-NOV-2018, sequence version 1.
DT   03-AUG-2022, entry version 15.
DE   RecName: Full=Delta(6)-protoilludene synthase 18 {ECO:0000303|PubMed:30105900};
DE            EC=4.2.3.135 {ECO:0000269|PubMed:30105900};
DE   AltName: Full=Terpene cyclase 18 {ECO:0000303|PubMed:30105900};
GN   Name=STS-18 {ECO:0000303|PubMed:30105900};
OS   Postia placenta (strain ATCC 44394 / Madison 698-R) (Brown rot fungus)
OS   (Poria monticola).
OC   Eukaryota; Fungi; Dikarya; Basidiomycota; Agaricomycotina; Agaricomycetes;
OC   Polyporales; Dacryobolaceae; Postia.
OX   NCBI_TaxID=561896;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, DOMAIN, AND CATALYTIC ACTIVITY.
RC   STRAIN=ATCC 44394 / Madison 698-R;
RX   PubMed=30105900; DOI=10.1111/1751-7915.13304;
RA   Ichinose H., Kitaoka T.;
RT   "Insight into metabolic diversity of the brown-rot basidiomycete Postia
RT   placenta responsible for sesquiterpene biosynthesis: semi-comprehensive
RT   screening of cytochrome P450 monooxygenase involved in protoilludene
RT   metabolism.";
RL   Microb. Biotechnol. 11:952-965(2018).
CC   -!- FUNCTION: Terpene cyclase that catalyzes the cyclization of farnesyl
CC       diphosphate (FPP) to delta(6)-protoilludene.
CC       {ECO:0000269|PubMed:30105900}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(2E,6E)-farnesyl diphosphate = Delta(6)-protoilludene +
CC         diphosphate; Xref=Rhea:RHEA:34695, ChEBI:CHEBI:33019,
CC         ChEBI:CHEBI:68655, ChEBI:CHEBI:175763; EC=4.2.3.135;
CC         Evidence={ECO:0000269|PubMed:30105900};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:34696;
CC         Evidence={ECO:0000269|PubMed:30105900};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000250|UniProtKB:I3ZNU9};
CC   -!- DOMAIN: The conserved DDXXD and NSE/DTE motifs are important for the
CC       catalytic activity, presumably through binding to Mg(2+).
CC       {ECO:0000305|PubMed:30105900}.
CC   -!- SIMILARITY: Belongs to the terpene synthase family. {ECO:0000305}.
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DR   EMBL; LC378436; BBD74528.1; -; mRNA.
DR   AlphaFoldDB; A0A348B790; -.
DR   SMR; A0A348B790; -.
DR   GO; GO:0016829; F:lyase activity; IEA:UniProtKB-KW.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   Gene3D; 1.10.600.10; -; 1.
DR   InterPro; IPR008949; Isoprenoid_synthase_dom_sf.
DR   InterPro; IPR034686; Terpene_cyclase-like_2.
DR   SFLD; SFLDG01020; Terpene_Cyclase_Like_2; 1.
DR   SUPFAM; SSF48576; SSF48576; 1.
PE   1: Evidence at protein level;
KW   Lyase; Magnesium; Metal-binding.
FT   CHAIN           1..348
FT                   /note="Delta(6)-protoilludene synthase 18"
FT                   /id="PRO_0000451394"
FT   MOTIF           87..91
FT                   /note="DDXXD motif"
FT                   /evidence="ECO:0000305|PubMed:30105900"
FT   MOTIF           223..231
FT                   /note="NSE/DTE motif"
FT                   /evidence="ECO:0000305|PubMed:30105900"
FT   BINDING         87
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   BINDING         87
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   BINDING         179
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   BINDING         223
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="3"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   BINDING         227
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="3"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   BINDING         231
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="3"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   BINDING         327..328
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:Q9UR08"
FT   SITE            84
FT                   /note="Plays a critical role in the stabilization of
FT                   intermediate cation"
FT                   /evidence="ECO:0000250|UniProtKB:B5HDJ6"
SQ   SEQUENCE   348 AA;  40000 MW;  4C963D206E006BF2 CRC64;
     MPSAIPMLYL PDTMSAWPWQ RAINPYFNEV KAASNSWFKS FRAFSPASQK AFDKCDFCLL
     AALAYPRARK EHLRTGCDLM NLFFVIDEYT DVEDANVCRD MVDIVIDALR RPHDPRPEGE
     VVLGEIARQF WARAIETASP TSQRRFLETF IAYLESVVLQ AADRDCDAEH TVQTYLAQRR
     DNIGSYPSYA VLELALDIPD DVFYHPAMNE LSLYATEMLI IDNDLVSYNR EQASGDTNNI
     LFVIMRQFNC SLDHAMAWAA AYHSQLEARF MDAFKRMPSW GLEIDSQVEE YCQGIANWPR
     GNDCWSFESG RYFGDKGREV QKTRCVPLLP KKERDTSLRQ QDVVITSL