ID   CAS1_BETPL              Reviewed;         767 AA.
AC   Q8W3Z4;
DT   16-NOV-2011, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2002, sequence version 1.
DT   25-MAY-2022, entry version 60.
DE   RecName: Full=Cycloartenol synthase;
DE            EC=5.4.99.8;
GN   Name=CASBPX1;
OS   Betula platyphylla (Asian white birch).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; fabids; Fagales; Betulaceae; Betula.
OX   NCBI_TaxID=78630;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND CATALYTIC ACTIVITY.
RX   PubMed=12736505; DOI=10.1248/bpb.26.642;
RA   Zhang H., Shibuya M., Yokota S., Ebizuka Y.;
RT   "Oxidosqualene cyclases from cell suspension cultures of Betula platyphylla
RT   var. japonica: molecular evolution of oxidosqualene cyclases in higher
RT   plants.";
RL   Biol. Pharm. Bull. 26:642-650(2003).
CC   -!- FUNCTION: Oxidosqualene cyclase converting oxidosqualene to
CC       cycloartenol. {ECO:0000269|PubMed:12736505}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(S)-2,3-epoxysqualene = cycloartenol; Xref=Rhea:RHEA:21308,
CC         ChEBI:CHEBI:15441, ChEBI:CHEBI:17030; EC=5.4.99.8;
CC         Evidence={ECO:0000269|PubMed:12736505};
CC   -!- SIMILARITY: Belongs to the terpene cyclase/mutase family.
CC       {ECO:0000305}.
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DR   EMBL; AB055509; BAB83085.1; -; mRNA.
DR   AlphaFoldDB; Q8W3Z4; -.
DR   SMR; Q8W3Z4; -.
DR   GO; GO:0005811; C:lipid droplet; IEA:InterPro.
DR   GO; GO:0016871; F:cycloartenol synthase activity; IDA:UniProtKB.
DR   GO; GO:0010686; P:tetracyclic 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   SFLD; SFLDG01016; Prenyltransferase_Like_2; 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..767
FT                   /note="Cycloartenol synthase"
FT                   /id="PRO_0000413990"
FT   REPEAT          158..199
FT                   /note="PFTB 1"
FT   REPEAT          522..567
FT                   /note="PFTB 2"
FT   REPEAT          599..639
FT                   /note="PFTB 3"
FT   REPEAT          648..689
FT                   /note="PFTB 4"
FT   REPEAT          710..751
FT                   /note="PFTB 5"
FT   REGION          1..22
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        493
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
SQ   SEQUENCE   767 AA;  87606 MW;  759E281855669606 CRC64;
     MWKLKIGAET ARGDGGGGGG SETWLRSLNN HLGRQIWEFH PELGTQEELQ QIDDARRRFW
     ERRFERRHSS DLLMRIQFAK ENPSSANIPQ VKIKDTEEVR EEAVGMTLRR AINFYSTIQA
     DDGHWPGDYG GPMFLIPGLV ITLSITGTLN AFLSKEHQCE ICRYLYNHQN EDGGWGLHIE
     GPSTMFGTAL NYITLRLLGE PEDGMGAVEK ARKWILDHGG ATAITSWGKM WLSVLGVYEW
     SGNNPLPPEV WLCPYLLPCH PGRMWCHCRM VYLPMSYLYG KRFVGPITST IQSLRKELYT
     VPYHEIDWNK ARNDCAKEDL YYPHPLVQDI LWASLYYAYE PIFMYWPAKR LREKALDTVM
     QHIHYEDENT RYICIGPVNK VLNMLCCWAE DPNSEAFKLH LPRILDYLWI AEDGMKMQGY
     NGSQLWDTTF AVQAIISTNI AEEYGQTLRK AHEYIKDSQV LEDCPGDLNF WYRHISKGAW
     PFSTADHGWP ISDCTAEGLK AVILLSQFPS ETVGKSVDVK RLYDAVHVIL SLQNTDGGFA
     TYELTRSYHW LELINPAETF GDIVIDYPYV ECTSAAIQAL TLFKKLHPGH RREEIENCIA
     KAAEFIENIQ ASDGSWYGSW GVCFTYAGWF GIKGLVAAGR TYKNCSSIHK ACDYLLSKEL
     ASGGWGESYL SCQDKVYTNL KDNRPHIVNT GWAMLALIDA GQAERDPTPL HRAARILINS
     QMENGDFPQE EIMGVFNKNC MISYSAYRNI FPIWALGEYR CRVLKAL