ID   CXE2_PAPSO              Reviewed;         313 AA.
AC   A0A0A1EQ07;
DT   03-JUL-2019, integrated into UniProtKB/Swiss-Prot.
DT   04-FEB-2015, sequence version 1.
DT   25-MAY-2022, entry version 13.
DE   RecName: Full=3-O-acetylpapaveroxine carboxylesterase CXE2 {ECO:0000305};
DE            EC=3.1.1.105 {ECO:0000269|PubMed:25485687};
DE   AltName: Full=Carboxylesterase 2 {ECO:0000303|PubMed:25485687};
GN   Name=CXE2 {ECO:0000303|PubMed:25485687};
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 [MRNA], FUNCTION, CATALYTIC ACTIVITY, AND
RP   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).
CC   -!- FUNCTION: Carboxylesterase involved in the biosynthesis of the
CC       benzylisoquinoline alkaloid noscapine (PubMed:25485687). Converts 3-O-
CC       acetylpapaveroxine to narcotine hemiacetal (PubMed:25485687).
CC       {ECO:0000269|PubMed:25485687}.
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};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:57401;
CC         Evidence={ECO:0000305|PubMed:25485687};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=25.2 uM for 3-O-acetylpapaveroxine {ECO:0000269|PubMed:25485687};
CC         Vmax=1535 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; KJ890443; AIY34373.1; -; mRNA.
DR   AlphaFoldDB; A0A0A1EQ07; -.
DR   SMR; A0A0A1EQ07; -.
DR   EnsemblPlants; RZC84724; RZC84724; C5167_047503.
DR   Gramene; RZC84724; RZC84724; C5167_047503.
DR   OMA; ADSTINH; -.
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..313
FT                   /note="3-O-acetylpapaveroxine carboxylesterase CXE2"
FT                   /id="PRO_0000447603"
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   313 AA;  35154 MW;  6CE2F936013BAA94 CRC64;
     MADPYEFLMC IHDPEEDTLT RNFPIPATPL DQNTKDISLN LDRKTSLRIF RPPTEEFCVT
     TNKLLPIIIY FHGGGFVLFN ADSTINHDFC QSIATHLPAL VVSVDYRLAP ENRLPAAYDD
     AVDALNWVKD QGLGKLNNSE VWLKEYGDFS KCFIMGCSSG GNIAYHASLR AIEMDLEPVI
     INGLILHSPF FGSLQRTESD LKVINDQDLP LAVRDVMWEL ALPLGSSRDH VYCNPNIAND
     GSSSGNMAGL IKRCLVIGFY GDPLIDRQIQ LVKMLEEKGV KVETWIEQEG YHGVPCFDPK
     IRETLLGKIK YFI