ID   AT2_CROXC               Reviewed;         433 AA.
AC   A0A2Z5CVK5;
DT   16-OCT-2019, integrated into UniProtKB/Swiss-Prot.
DT   10-OCT-2018, sequence version 1.
DT   03-AUG-2022, entry version 11.
DE   RecName: Full=Myricetin 3-O-glucosyl 1,2-rhamnoside 6'-O-caffeoyltransferase AT2 {ECO:0000305};
DE            EC=2.3.1.- {ECO:0000269|PubMed:29967287};
DE   AltName: Full=Acyltransferase 2 {ECO:0000303|PubMed:29967287};
DE            Short=CcAT2 {ECO:0000303|PubMed:29967287};
GN   Name=AT2 {ECO:0000303|PubMed:29967287};
OS   Crocosmia x crocosmiiflora (Montbretia) (Crocosmia aurea x Crocosmia
OS   pottsii).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Asparagales; Iridaceae;
OC   Crocoideae; Freesieae; Crocosmia.
OX   NCBI_TaxID=1053288;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, AND TISSUE
RP   SPECIFICITY.
RX   PubMed=29967287; DOI=10.1105/tpc.18.00406;
RA   Irmisch S., Jo S., Roach C.R., Jancsik S., Man Saint Yuen M., Madilao L.L.,
RA   O'Neil-Johnson M., Williams R., Withers S.G., Bohlmann J.;
RT   "Discovery of UDP-glycosyltransferases and BAHD-acyltransferases involved
RT   in the biosynthesis of the antidiabetic plant metabolite montbretin A.";
RL   Plant Cell 30:1864-1886(2018).
CC   -!- FUNCTION: Caffeoyltransferase involved in montbretin A (MbA)
CC       biosynthesis (PubMed:29967287). Catalyzes the caffeoylation of
CC       myricetin 3-O-beta-D-glucosyl 1,2-alpha-L-rhamnoside (MRG) to produce
CC       myricetin 3-O-(6'-O-caffeoyl)-beta-D-glucosyl 1,2-alpha-L-rhamnoside
CC       (mini-MbA), a precursor of MbA (PubMed:29967287). Mini-MbA and MbA are
CC       potent inhibitors of human pancreatic alpha-amylase and are being
CC       developed as drug candidates to treat type-2 diabetes
CC       (PubMed:29967287). In vitro, is able to catalyze the caffeoylation of
CC       quercetin 3-O-sophoroside (QGG), although QGG may not be a
CC       physiological substrate in vivo (PubMed:29967287). In vitro, can use
CC       coumaryl-CoA, feruloyl-CoA and acetyl-CoA, although these three acyl
CC       donors may not be physiological in vivo (PubMed:29967287).
CC       {ECO:0000269|PubMed:29967287}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(E)-caffeoyl-CoA + myricetin 3-O-[beta-D-glucosyl-(1->2)-
CC         alpha-L-rhamnoside] = CoA + myricetin 3-O-[(6-O-(E)-caffeoyl-beta-D-
CC         glucosyl)-(1->2)-alpha-L-rhamnoside]; Xref=Rhea:RHEA:61152,
CC         ChEBI:CHEBI:57287, ChEBI:CHEBI:87136, ChEBI:CHEBI:144428,
CC         ChEBI:CHEBI:144429; Evidence={ECO:0000269|PubMed:29967287};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:61153;
CC         Evidence={ECO:0000269|PubMed:29967287};
CC   -!- PATHWAY: Flavonoid metabolism. {ECO:0000305}.
CC   -!- TISSUE SPECIFICITY: Expressed in young cromes.
CC       {ECO:0000269|PubMed:29967287}.
CC   -!- SIMILARITY: Belongs to the plant acyltransferase family. {ECO:0000305}.
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DR   EMBL; MH365463; AXB26762.1; -; mRNA.
DR   AlphaFoldDB; A0A2Z5CVK5; -.
DR   SMR; A0A2Z5CVK5; -.
DR   GO; GO:0016747; F:acyltransferase activity, transferring groups other than amino-acyl groups; IEA:UniProt.
DR   Gene3D; 3.30.559.10; -; 2.
DR   InterPro; IPR023213; CAT-like_dom_sf.
PE   1: Evidence at protein level;
KW   Acyltransferase; Transferase.
FT   CHAIN           1..433
FT                   /note="Myricetin 3-O-glucosyl 1,2-rhamnoside 6'-O-
FT                   caffeoyltransferase AT2"
FT                   /id="PRO_0000448220"
FT   ACT_SITE        157
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250|UniProtKB:Q8W1W9"
FT   ACT_SITE        375
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250|UniProtKB:Q8W1W9"
SQ   SEQUENCE   433 AA;  48138 MW;  E936D485E98C15B8 CRC64;
     MSFTVTKTAP AVITPSEPTP SGHILPLSFF DRLPFLRVFL VDMIMVYGHG DQPAKVIKEA
     VAKALVHYYP LAGRLTTDTD DGELSVACTG EGVWFVEATA DCRMEDVNYL QVEPLMIPKE
     QILPSHPEGV DPYTLPFMIQ VTQFRCGGFT FATRANHAVF DGIGAGQIKV AIGEMARGLK
     HPTVKPVWCR DVIRKPIPSQ ISATEPHDTD LSSIPDLKFT NNQTNIECCS FDLSLDHINH
     LKDHFAKEVG KICSVFDVIA AKLWQSRTRA IGLQPQTEVS LTFLLNIRQV VLHNELPPDG
     GYYGNCLVPL INKAPSGQIA NAPLFEIVRL IKEAKDDLLS KDSASLIGEM PPYKKPSYAD
     LSIVDWRRLG LYEADFGWGG PMFLVPLNEH TVTSCSTYLF KSPVASKKDV RLVTYCIVKE
     HLEAFRDEMN DFT