ID   CAS2_BETPL              Reviewed;         757 AA.
AC   Q8W3Z3;
DT   16-NOV-2011, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2002, sequence version 1.
DT   25-MAY-2022, entry version 54.
DE   RecName: Full=Cycloartenol synthase 2;
DE            EC=5.4.99.8;
GN   Name=CASBPX2;
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; AB055510; BAB83086.1; -; mRNA.
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..757
FT                   /note="Cycloartenol synthase 2"
FT                   /id="PRO_0000413991"
FT   REPEAT          147..188
FT                   /note="PFTB 1"
FT   REPEAT          512..557
FT                   /note="PFTB 2"
FT   REPEAT          589..629
FT                   /note="PFTB 3"
FT   REPEAT          638..679
FT                   /note="PFTB 4"
FT   REPEAT          700..741
FT                   /note="PFTB 5"
FT   ACT_SITE        483
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
SQ   SEQUENCE   757 AA;  86235 MW;  4D7464A55F588168 CRC64;
     MWKLKIAEGG SPWLRTLNNH VGRQVWEFDP KLGSPEELAE IERARETSLK VRFEKKHSSD
     LLMRIQFAKE NPRGAVLPQV KVNETEDVTE EMVTRMLRRA ISFHSTLQAH DGHWAGDYGG
     PMFLMPGLVI TLSITGALNT VLSEEHKKEM CRYLYNHQNK DGGWGLHIEG PSTMFGTVLS
     YVTLRLLGEG ANDGQGAIER GRKWILDHGS ATAIISWGKM WLSVLGAFEW SGNNPLPPEI
     WLLPYMLPVH PGRMWCHCRM VYLPMSYLYG KRFVGPITPT VMSLRKELYS VPYHEIDWNQ
     ARNLCAKEXL YYPHPLVQDI LWASLHKLVE PVLMRWPGKR LREKALRTVL EHIHYEDENT
     RYICIGPVNK VLNMLCCWVE DPNSEAFKLH LPRINDYLWI AEDGMKMQGY NGSQLWDTAF
     AVQAIISTNL FEEYGPTLEK AHMYIKKSQV REDCPGDLDF WYRHISKGAW PFSTADHGWP
     ISDCTAEGLK AALLLSKIPP DVVGEPLVEE RLYDAVNVIL SLQNADGGFA TYELTRSYPW
     LELINPAETF GDIVIDYNYV ECTSAAIQAL TSFKKSYPKH REEEVDVCIK RAAMFTEKIQ
     ASDGSWYGSW GVCFTYGTWF GVKGLVAAGK NFNDCFGIRK ACDFLLSKQL PSGGWGESYL
     SCQNKVYSHV EGNRSHVVNT GWAMLALIEA GQAERDPTPL HRAARVLINS QMENGDFPQE
     EIMGVFNRNC MITYAAYRNI FPIWALGEYR CRVLQAP