ID   BAMS_BETPL              Reviewed;         779 AA.
AC   Q8W3Z1;
DT   16-NOV-2011, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2002, sequence version 1.
DT   25-MAY-2022, entry version 61.
DE   RecName: Full=Beta-amyrin synthase;
DE            EC=5.4.99.39;
GN   Name=OSCBPY;
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 into beta-
CC       amyrin, generating five rings and eight asymmetric centers in a single
CC       transformation. {ECO:0000269|PubMed:12736505}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(S)-2,3-epoxysqualene = beta-amyrin; Xref=Rhea:RHEA:31007,
CC         ChEBI:CHEBI:10352, ChEBI:CHEBI:15441; EC=5.4.99.39;
CC         Evidence={ECO:0000269|PubMed:12736505};
CC   -!- SIMILARITY: Belongs to the terpene cyclase/mutase family.
CC       {ECO:0000305}.
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DR   EMBL; AB055512; BAB83088.1; -; mRNA.
DR   AlphaFoldDB; Q8W3Z1; -.
DR   SMR; Q8W3Z1; -.
DR   KEGG; ag:BAB83088; -.
DR   BRENDA; 5.4.99.39; 9789.
DR   GO; GO:0005811; C:lipid droplet; IEA:InterPro.
DR   GO; GO:0042300; F:beta-amyrin synthase activity; IDA:UniProtKB.
DR   GO; GO:0019745; P:pentacyclic 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..779
FT                   /note="Beta-amyrin synthase"
FT                   /id="PRO_0000413997"
FT   REPEAT          148..189
FT                   /note="PFTB 1"
FT   REPEAT          514..556
FT                   /note="PFTB 2"
FT   REPEAT          640..681
FT                   /note="PFTB 3"
FT   ACT_SITE        485
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
SQ   SEQUENCE   779 AA;  89558 MW;  2719195638B22B58 CRC64;
     MWRLKIADGG SDPYIYSTNN FVGRQTWEFD PQAGSPQERA EVEEARRNFY DNRYQVKPSG
     DLLWRMQFLK EKNFKQTIPP VKVEDGEEIT YEKSTAALRR AVHFYSALQA SDGHWPAENA
     GPLFFLPPLV MCMYITGHLN TVFPAEHQKE ILRYIYYHQN EDGGWGLHIE GHSTMFCTAL
     SYICMRILGE GPDGGQDNAC ARARKWILDH GGVTHMPSWG KTWLSILGIF EWIGSNPMPP
     EFWILPSFLP MHPAKMWCYC RMVYMPMSYL YGKRFVGPIT PLILQLREEL YTQPYHQVNW
     KKVRHLCAKE DIYYPHPLIQ DLLWDSLYIF TEPLLTRWPF NKLVREKALQ VTMKHIHYED
     ENSRYITIGC VEKVLCMLAC WVEDPNGDYF KKHIARIPDY IWVAEDGIKM QSFGSQEWDT
     GFAIQALLAS NLTDEIGPTL ARGHDFIKKS QVKDNPSGDF ESMHRHISKG SWTFSDQDHG
     WQVSDCTAEG LKCCLLFSIM PPEIVGEKME PEQLYDSVNV LLSLQSKNGG LAAWEPAGAQ
     EWLELLNSTE FFADIVIEHE YIECTASAMQ TLVLFKKLYP GHRKKEIENF IKNAAQFLQV
     IQMPDGSWYG NWGVCFTYGT WFALGGLAAV GKTYNNCLAV RRAVDFLLRA QRDNGGWGES
     YLSCPKKEYV PLEGNKSNLV HTAWAMMGLI HAGQAERDPT PLHRAAKLII NSQLEDGDFP
     QQEITGVFMK NCMLHYAAYK NIYPLWALAE YRKHVPLPLG KNLNQVVNCI GQSLYKKYK