ID   CFI_SAUME               Reviewed;         232 AA.
AC   Q8LKP9;
DT   11-SEP-2007, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2002, sequence version 1.
DT   03-AUG-2022, entry version 63.
DE   RecName: Full=Chalcone--flavanone isomerase;
DE            Short=Chalcone isomerase;
DE            EC=5.5.1.6;
GN   Name=CHI;
OS   Saussurea medusa (Saw-wort).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; campanulids; Asterales; Asteraceae; Carduoideae; Cardueae;
OC   Saussureinae; Saussurea.
OX   NCBI_TaxID=137893;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND FUNCTION.
RX   PubMed=16427667; DOI=10.1016/j.phytochem.2005.12.004;
RA   Li F.-X., Jin Z.-P., Zhao D.-X., Cheng L.-Q., Fu C.-X., Ma F.;
RT   "Overexpression of the Saussurea medusa chalcone isomerase gene in S.
RT   involucrata hairy root cultures enhances their biosynthesis of apigenin.";
RL   Phytochemistry 67:553-560(2006).
CC   -!- FUNCTION: Catalyzes the intramolecular cyclization of bicyclic
CC       chalcones into tricyclic (S)-flavanones. Responsible for the
CC       isomerization of 4,2',4',6'-tetrahydroxychalcone (also termed chalcone)
CC       into naringenin. {ECO:0000269|PubMed:16427667}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a chalcone = a flavanone.; EC=5.5.1.6;
CC   -!- PATHWAY: Secondary metabolite biosynthesis; flavonoid biosynthesis.
CC   -!- MISCELLANEOUS: Part of the biosynthetic pathway for all classes of
CC       flavonoids, a large class of secondary plant metabolites, many of which
CC       are brightly colored.
CC   -!- SIMILARITY: Belongs to the chalcone isomerase family. {ECO:0000305}.
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DR   EMBL; AF509335; AAM48130.1; -; mRNA.
DR   AlphaFoldDB; Q8LKP9; -.
DR   SMR; Q8LKP9; -.
DR   BRENDA; 5.5.1.6; 8086.
DR   UniPathway; UPA00154; -.
DR   GO; GO:0045430; F:chalcone isomerase activity; IEA:UniProtKB-EC.
DR   GO; GO:0009813; P:flavonoid biosynthetic process; IEA:UniProtKB-UniPathway.
DR   Gene3D; 1.10.890.20; -; 1.
DR   Gene3D; 3.50.70.10; -; 1.
DR   InterPro; IPR044164; CFI.
DR   InterPro; IPR016087; Chalcone_isomerase.
DR   InterPro; IPR016088; Chalcone_isomerase_3-sand.
DR   InterPro; IPR016089; Chalcone_isomerase_bundle_sf.
DR   InterPro; IPR036298; Chalcone_isomerase_sf.
DR   PANTHER; PTHR28039; PTHR28039; 1.
DR   Pfam; PF02431; Chalcone; 1.
DR   SUPFAM; SSF54626; SSF54626; 1.
PE   2: Evidence at transcript level;
KW   Flavonoid biosynthesis; Isomerase.
FT   CHAIN           1..232
FT                   /note="Chalcone--flavanone isomerase"
FT                   /id="PRO_0000300849"
FT   BINDING         50
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         192
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   SITE            108
FT                   /note="Important for catalytic activity"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   232 AA;  24941 MW;  188763B425AFA001 CRC64;
     MAPPPSSTSI QVESIVFPPS VKPPGATTTL FLGGAGVRGM EIQGNFVKFT GIGVYLEDKA
     IPSLAVKWKG KTAAELTDSV QFYRDIVTGP FEKFSQVTMI LPLTGKQYSE KVSEMCIGVW
     KAQGTYTDAD TATIEKFLEV FKDENFLPGS SILFTTSPTG SLTISFSKDG NIPEAATVVL
     ENRKLAQTVI ESVIGEHGVS PEAKQSLASR LSDFMTQFDE KATANVESQI GL