ID   CXE1_PAPSO              Reviewed;         320 AA.
AC   I3PLR2;
DT   03-JUL-2019, integrated into UniProtKB/Swiss-Prot.
DT   05-SEP-2012, sequence version 1.
DT   03-AUG-2022, entry version 22.
DE   RecName: Full=3-O-acetylpapaveroxine carboxylesterase CXE1 {ECO:0000305};
DE            EC=3.1.1.105 {ECO:0000269|PubMed:25485687, ECO:0000269|PubMed:27378283};
DE   AltName: Full=Carboxylesterase 1 {ECO:0000303|PubMed:22653730};
GN   Name=CXE1 {ECO:0000303|PubMed:22653730};
OS   Papaver somniferum (Opium poppy).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Ranunculales; Papaveraceae; Papaveroideae;
OC   Papaver.
OX   NCBI_TaxID=3469;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=22653730; DOI=10.1126/science.1220757;
RA   Winzer T., Gazda V., He Z., Kaminski F., Kern M., Larson T.R., Li Y.,
RA   Meade F., Teodor R., Vaistij F.E., Walker C., Bowser T.A., Graham I.A.;
RT   "A Papaver somniferum 10-gene cluster for synthesis of the anticancer
RT   alkaloid noscapine.";
RL   Science 336:1704-1708(2012).
RN   [2]
RP   FUNCTION, CATALYTIC ACTIVITY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RX   PubMed=25485687; DOI=10.1038/nchembio.1717;
RA   Dang T.T., Chen X., Facchini P.J.;
RT   "Acetylation serves as a protective group in noscapine biosynthesis in
RT   opium poppy.";
RL   Nat. Chem. Biol. 11:104-106(2015).
RN   [3]
RP   FUNCTION, AND CATALYTIC ACTIVITY.
RX   PubMed=27378283; DOI=10.1038/ncomms12137;
RA   Li Y., Smolke C.D.;
RT   "Engineering biosynthesis of the anticancer alkaloid noscapine in yeast.";
RL   Nat. Commun. 7:12137-12137(2016).
RN   [4]
RP   FUNCTION.
RX   PubMed=29610307; DOI=10.1073/pnas.1721469115;
RA   Li Y., Li S., Thodey K., Trenchard I., Cravens A., Smolke C.D.;
RT   "Complete biosynthesis of noscapine and halogenated alkaloids in yeast.";
RL   Proc. Natl. Acad. Sci. U.S.A. 115:E3922-E3931(2018).
CC   -!- FUNCTION: Carboxylesterase involved in the biosynthesis of the
CC       benzylisoquinoline alkaloid noscapine (PubMed:25485687,
CC       PubMed:27378283, PubMed:29610307). Converts 3-O-acetylpapaveroxine to
CC       papaveroxine which spontaneously rearranges to narcotine hemiacetal
CC       (PubMed:25485687, PubMed:27378283). {ECO:0000269|PubMed:25485687,
CC       ECO:0000269|PubMed:27378283, ECO:0000269|PubMed:29610307}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=3-O-acetylpapaveroxine + H2O = acetate + H(+) + narcotine
CC         hemiacetal; Xref=Rhea:RHEA:57400, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:30089, ChEBI:CHEBI:141645,
CC         ChEBI:CHEBI:141667; EC=3.1.1.105;
CC         Evidence={ECO:0000269|PubMed:25485687, ECO:0000269|PubMed:27378283};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:57401;
CC         Evidence={ECO:0000305|PubMed:25485687};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=47 uM for 3-O-acetylpapaveroxine {ECO:0000269|PubMed:25485687};
CC         Vmax=336 nmol/min/mg enzyme with 3-O-acetylpapaveroxine as substrate
CC         {ECO:0000269|PubMed:25485687};
CC   -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the 'GDXG' lipolytic enzyme family.
CC       {ECO:0000305}.
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DR   EMBL; JQ659006; AFB74618.1; -; Genomic_DNA.
DR   AlphaFoldDB; I3PLR2; -.
DR   SMR; I3PLR2; -.
DR   EnsemblPlants; RZC84728; RZC84728; C5167_047504.
DR   Gramene; RZC84728; RZC84728; C5167_047504.
DR   KEGG; ag:AFB74618; -.
DR   BioCyc; MetaCyc:MON-17771; -.
DR   BRENDA; 3.1.1.105; 4515.
DR   GO; GO:0016787; F:hydrolase activity; IEA:UniProtKB-KW.
DR   GO; GO:0009820; P:alkaloid metabolic process; IEA:UniProtKB-KW.
DR   Gene3D; 3.40.50.1820; -; 1.
DR   InterPro; IPR029058; AB_hydrolase.
DR   InterPro; IPR013094; AB_hydrolase_3.
DR   InterPro; IPR002168; Lipase_GDXG_HIS_AS.
DR   Pfam; PF07859; Abhydrolase_3; 1.
DR   SUPFAM; SSF53474; SSF53474; 1.
DR   PROSITE; PS01173; LIPASE_GDXG_HIS; 1.
PE   1: Evidence at protein level;
KW   Alkaloid metabolism; Hydrolase.
FT   CHAIN           1..320
FT                   /note="3-O-acetylpapaveroxine carboxylesterase CXE1"
FT                   /id="PRO_0000447602"
FT   MOTIF           72..74
FT                   /note="Involved in the stabilization of the negatively
FT                   charged intermediate by the formation of the oxyanion hole"
FT                   /evidence="ECO:0000250|UniProtKB:Q5NUF3"
FT   ACT_SITE        158
FT                   /evidence="ECO:0000250|UniProtKB:Q5NUF3"
FT   ACT_SITE        262
FT                   /evidence="ECO:0000250|UniProtKB:Q5NUF3"
FT   ACT_SITE        292
FT                   /evidence="ECO:0000250|UniProtKB:Q5NUF3"
SQ   SEQUENCE   320 AA;  36168 MW;  3C9E90A4460DD39A CRC64;
     MADPYEFLMC IHNPEEDTLT RNFPIPATPL DQNTKDISLN PDRKTSLRIF RPPTKEPPVT
     KNKLLPIIIY FHGGGFILFN ADSTMNHDFC QSIATHIPAL VVSVDYRLAP ENRLPAAYDD
     AVDALNWVKD QGLGKLNNSE VWLKEYGDFS KCFIMGCSSG ANVAYHASLR AIEMDLEPAK
     INGLILHCPF FGSLERTESD SKVINNQDLP LAVRDVMWEL ALPLGSTRDH VYCNPNIDHD
     GSSSGNMVGL IERCFVVGFY GDPLIDRQIQ LVKMLEEKGV KVETWIEQGG YHGVLCFDPM
     IRETFLEKLK HFILNDEFIY