ID   CRTW_HAELA              Reviewed;         320 AA.
AC   Q39982;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 56.
DE   RecName: Full=Beta-carotene ketolase;
DE            EC=1.14.99.63;
DE   AltName: Full=Beta-carotene oxygenase;
OS   Haematococcus lacustris (Green alga) (Haematococcus pluvialis).
OC   Eukaryota; Viridiplantae; Chlorophyta; core chlorophytes; Chlorophyceae;
OC   CS clade; Chlamydomonadales; Haematococcaceae; Haematococcus.
OX   NCBI_TaxID=44745;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=NIES-144 / IAM C-392 / MKF-8;
RX   PubMed=7579184; DOI=10.1007/bf00043657;
RA   Kajiwara S., Kakizono T., Saito T., Kondo K., Ohtani T., Nishio N.,
RA   Nagai S., Misawa N.;
RT   "Isolation and functional identification of a novel cDNA for astaxanthin
RT   biosynthesis from Haematococcus pluvialis, and astaxanthin synthesis in
RT   Escherichia coli.";
RL   Plant Mol. Biol. 29:343-352(1995).
CC   -!- FUNCTION: Converts beta-carotene to canthaxanthin via echinenone.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 AH2 + all-trans-beta-carotene + 2 O2 = 2 A + echinenone + 3
CC         H2O; Xref=Rhea:RHEA:55660, ChEBI:CHEBI:4746, ChEBI:CHEBI:13193,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15379, ChEBI:CHEBI:17499,
CC         ChEBI:CHEBI:17579; EC=1.14.99.63;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 AH2 + echinenone + 2 O2 = 2 A + canthaxanthin + 3 H2O;
CC         Xref=Rhea:RHEA:55664, ChEBI:CHEBI:3362, ChEBI:CHEBI:4746,
CC         ChEBI:CHEBI:13193, ChEBI:CHEBI:15377, ChEBI:CHEBI:15379,
CC         ChEBI:CHEBI:17499; EC=1.14.99.63;
CC   -!- PATHWAY: Carotenoid biosynthesis; astaxanthin biosynthesis.
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DR   EMBL; D45881; BAA08300.1; -; mRNA.
DR   PIR; S65078; S65078.
DR   AlphaFoldDB; Q39982; -.
DR   BioCyc; MetaCyc:MON-19179; -.
DR   BRENDA; 1.14.99.63; 2522.
DR   UniPathway; UPA00387; -.
DR   GO; GO:0016491; F:oxidoreductase activity; IEA:UniProtKB-KW.
DR   GO; GO:0016117; P:carotenoid biosynthetic process; IEA:UniProtKB-KW.
DR   InterPro; IPR005804; FA_desaturase_dom.
DR   InterPro; IPR012171; Fatty_acid_desaturase.
DR   PANTHER; PTHR19353; PTHR19353; 2.
DR   Pfam; PF00487; FA_desaturase; 2.
PE   2: Evidence at transcript level;
KW   Carotenoid biosynthesis; Oxidoreductase.
FT   CHAIN           1..320
FT                   /note="Beta-carotene ketolase"
FT                   /id="PRO_0000079372"
SQ   SEQUENCE   320 AA;  35989 MW;  4F4D8669BD326527 CRC64;
     MHVASALMVE QKGSEAAASS PDVLRAWATQ YHMPSESSDA ARPALKHAYK PPASDAKGIT
     MALTIIGTWT AVFLHAIFQI RLPTSMDQLH WLPVSEATAQ LLGGSSSLLH IAAVFIVLEF
     LYTGLFITTH DAMHGTIALR HRQLNDLLGN ICISLYAWFD YSMLHRKHWE HHNHTGEVGK
     DPDFHKGNPG LVPWFASFMS SYMSLWQFAR LAWWAVVMQM LGAPMANLLV FMAAAPILSA
     FRLFYFGTYL PHKPEPGPAA GSQVMAWFRA KTSEASDVMS FLTCYHFDLH WEHHRWPFAP
     WWQLPHCRRL SGRGLVPALA