ID   LCD_LYCCL               Reviewed;         766 AA.
AC   A0A125SXN2;
DT   07-NOV-2018, integrated into UniProtKB/Swiss-Prot.
DT   13-APR-2016, sequence version 1.
DT   25-MAY-2022, entry version 20.
DE   RecName: Full=Alpha-onocerin synthase LCD {ECO:0000303|PubMed:26663356};
DE            EC=5.4.99.66 {ECO:0000269|PubMed:26663356};
GN   Name=LCD {ECO:0000303|PubMed:26663356};
OS   Lycopodium clavatum (Stag's-horn clubmoss).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Lycopodiopsida; Lycopodiales; Lycopodiaceae; Lycopodioideae; Lycopodium.
OX   NCBI_TaxID=3252;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, AND PATHWAY.
RX   PubMed=26663356; DOI=10.1002/cbic.201500663;
RA   Araki T., Saga Y., Marugami M., Otaka J., Araya H., Saito K., Yamazaki M.,
RA   Suzuki H., Kushiro T.;
RT   "Onocerin biosynthesis requires two highly dedicated triterpene cyclases in
RT   a fern Lycopodium clavatum.";
RL   ChemBioChem 17:288-290(2016).
CC   -!- FUNCTION: Oxidosqualene cyclase involved in the biosynthesis of alpha-
CC       onocerin, a triterpenoid characterized by a symmetrical structure due
CC       to cyclizations at both termini of dioxidosqualene that inhibits
CC       acetylcholinesterase. Catalyzes the second half of the cyclization,
CC       exclusively from pre-alpha-onocerin. {ECO:0000269|PubMed:26663356}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=pre-alpha-onocerin = alpha-onocerin; Xref=Rhea:RHEA:54668,
CC         ChEBI:CHEBI:138303, ChEBI:CHEBI:138305; EC=5.4.99.66;
CC         Evidence={ECO:0000269|PubMed:26663356};
CC   -!- PATHWAY: Secondary metabolite biosynthesis; terpenoid biosynthesis.
CC       {ECO:0000269|PubMed:26663356}.
CC   -!- SIMILARITY: Belongs to the terpene cyclase/mutase family.
CC       {ECO:0000305}.
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DR   EMBL; LC053636; BAU46472.1; -; mRNA.
DR   AlphaFoldDB; A0A125SXN2; -.
DR   SMR; A0A125SXN2; -.
DR   KEGG; ag:BAU46472; -.
DR   BRENDA; 5.4.99.66; 3106.
DR   UniPathway; UPA00213; -.
DR   GO; GO:0005811; C:lipid droplet; IEA:InterPro.
DR   GO; GO:0016866; F:intramolecular transferase activity; IEA:InterPro.
DR   GO; GO:0016104; P:triterpenoid biosynthetic process; IDA:UniProtKB.
DR   CDD; cd02892; SQCY_1; 1.
DR   InterPro; IPR032696; SQ_cyclase_C.
DR   InterPro; IPR032697; SQ_cyclase_N.
DR   InterPro; IPR018333; Squalene_cyclase.
DR   InterPro; IPR002365; Terpene_synthase_CS.
DR   InterPro; IPR008930; Terpenoid_cyclase/PrenylTrfase.
DR   PANTHER; PTHR11764; PTHR11764; 1.
DR   Pfam; PF13243; SQHop_cyclase_C; 1.
DR   Pfam; PF13249; SQHop_cyclase_N; 1.
DR   SUPFAM; SSF48239; SSF48239; 2.
DR   TIGRFAMs; TIGR01787; squalene_cyclas; 1.
DR   PROSITE; PS01074; TERPENE_SYNTHASES; 1.
PE   1: Evidence at protein level;
KW   Isomerase; Repeat.
FT   CHAIN           1..766
FT                   /note="Alpha-onocerin synthase LCD"
FT                   /id="PRO_0000445705"
FT   REPEAT          101..143
FT                   /note="PFTB 1"
FT                   /evidence="ECO:0000255"
FT   REPEAT          151..192
FT                   /note="PFTB 2"
FT                   /evidence="ECO:0000255"
FT   REPEAT          456..507
FT                   /note="PFTB 3"
FT                   /evidence="ECO:0000255"
FT   REPEAT          517..558
FT                   /note="PFTB 4"
FT                   /evidence="ECO:0000255"
FT   REPEAT          594..634
FT                   /note="PFTB 5"
FT                   /evidence="ECO:0000255"
FT   REPEAT          643..684
FT                   /note="PFTB 6"
FT                   /evidence="ECO:0000255"
FT   REPEAT          705..752
FT                   /note="PFTB 7"
FT                   /evidence="ECO:0000255"
FT   ACT_SITE        488
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
FT   SITE            421
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
FT   SITE            615
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
SQ   SEQUENCE   766 AA;  87194 MW;  5F87C4E324A997ED CRC64;
     MWRLRTGSST VDKADSWLSS LNNHLGRQIW CYDPEAGTPQ EREAVEAECA RFTANRHQQR
     QSADTLLRLQ FQKEHSANRL PSRITVNEDH EVTEDDVTTT LCRALQFYSQ LQTDDGHWSG
     DHSGPMFFLP GMVIALYVTG ALDSVLSEHH QREICRYIYN HQRQDGSWGL HPEGTGTLFG
     TVLSYVTLRL MGESKSNSNN REALRKAQTW IIDHGGATDV PSWGKFWLAV LGVYEWSGVN
     PLPPESWLLP KSLIAHPGRL PVLYRFIFLP MSYIYARRLS HHLTKIIEDL RKELYTIPYE
     DIDWNHARKL GAKEEIVPRS VVQDVILSIL HNYVEPIMSH WPGFLLRQKA LALIMEHIHH
     EDETTQYLCV CPVSKALNML CCWLEDRNSD AFKKHLSRVL DFLWLSEDGM KMQVCNGSQL
     WDTALSVRAL ISANLLNECS SMLRRAKLYI ENTQIQESYP GDLDHWHRIT SKGGWPQSTR
     DWGWPVSDCT AEALQAVLAL SSQSTTDVGE ALPEERIHEC INVLLSFQKS NGSFAPFDAR
     NPLEGPKIWN HTESPGYKSL DFECVECTSS VIQALAAFNK IYPEHRAKEI SISIQEGTRF
     IERLQNSDGS WSGTWGICFT YATWFGIMGL LASGARYYES IAIQRACEFI LSKQLPNGGW
     GEHFHSFKNK VYTNLEGERA HVVHTSWSML ALLATGQEGR DAIPLHRAAK ILINAQMETG
     DYSQEGVVGA VCGDHTISYA TYRCVFPIWA LGEYRYKLFG KKNMYI