ID   HO_GUITH                Reviewed;         237 AA.
AC   O78497;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1998, sequence version 1.
DT   03-AUG-2022, entry version 97.
DE   RecName: Full=Heme oxygenase;
DE            EC=1.14.14.18 {ECO:0000250|UniProtKB:O48782};
GN   Name=pbsA;
OS   Guillardia theta (Cryptophyte) (Cryptomonas phi).
OG   Plastid; Chloroplast.
OC   Eukaryota; Cryptophyceae; Pyrenomonadales; Geminigeraceae; Guillardia.
OX   NCBI_TaxID=55529;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=9929392; DOI=10.1007/pl00006462;
RA   Douglas S.E., Penny S.L.;
RT   "The plastid genome of the cryptophyte alga, Guillardia theta: complete
RT   sequence and conserved synteny groups confirm its common ancestry with red
RT   algae.";
RL   J. Mol. Evol. 48:236-244(1999).
CC   -!- FUNCTION: Catalyzes the opening of the heme ring with the release of
CC       iron. Key enzyme in the synthesis of the chromophoric part of the
CC       photosynthetic antennae.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=heme b + 3 O2 + 3 reduced [NADPH--hemoprotein reductase] =
CC         biliverdin IXalpha + CO + Fe(2+) + H(+) + 3 H2O + 3 oxidized [NADPH--
CC         hemoprotein reductase]; Xref=Rhea:RHEA:21764, Rhea:RHEA-COMP:11964,
CC         Rhea:RHEA-COMP:11965, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:15379, ChEBI:CHEBI:17245, ChEBI:CHEBI:29033,
CC         ChEBI:CHEBI:57618, ChEBI:CHEBI:57991, ChEBI:CHEBI:58210,
CC         ChEBI:CHEBI:60344; EC=1.14.14.18;
CC         Evidence={ECO:0000250|UniProtKB:O48782};
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
CC   -!- SIMILARITY: Belongs to the heme oxygenase family. {ECO:0000305}.
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DR   EMBL; AF041468; AAC35688.1; -; Genomic_DNA.
DR   RefSeq; NP_050754.1; NC_000926.1.
DR   AlphaFoldDB; O78497; -.
DR   SMR; O78497; -.
DR   GeneID; 857059; -.
DR   HOGENOM; CLU_057050_2_0_1; -.
DR   OMA; KKSHTMA; -.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0004392; F:heme oxygenase (decyclizing) activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0006788; P:heme oxidation; IEA:InterPro.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW.
DR   CDD; cd19165; HemeO; 1.
DR   Gene3D; 1.20.910.10; -; 1.
DR   InterPro; IPR002051; Haem_Oase.
DR   InterPro; IPR016053; Haem_Oase-like.
DR   InterPro; IPR016084; Haem_Oase-like_multi-hlx.
DR   InterPro; IPR018207; Haem_oxygenase_CS.
DR   PANTHER; PTHR10720; PTHR10720; 1.
DR   Pfam; PF01126; Heme_oxygenase; 1.
DR   PIRSF; PIRSF000343; Haem_Oase; 1.
DR   PRINTS; PR00088; HAEMOXYGNASE.
DR   SUPFAM; SSF48613; SSF48613; 1.
DR   PROSITE; PS00593; HEME_OXYGENASE; 1.
PE   3: Inferred from homology;
KW   Chloroplast; Heme; Iron; Metal-binding; Oxidoreductase; Photosynthesis;
KW   Plastid.
FT   CHAIN           1..237
FT                   /note="Heme oxygenase"
FT                   /id="PRO_0000209698"
FT   BINDING         17
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   237 AA;  27631 MW;  CBDD4D045A7B8890 CRC64;
     MSNNLAIQLR EGTSKSHSMA ENVSFVKSFL SGVIDTNSYK KMMSNLYFVY KAMEEEMEYH
     KENDLIKPIY FVELNRSESL ALDLNFYYGD TWKDIIEPSE ATRVYINRIK KISKEKPLLL
     IAHAYTRYLG DLSGGQILKK IAQRALNVPN SQGLAFYEFD KIDDEQAFKQ KYKKALDTLP
     VTDKMISQIV AEANIAFNLN MRMFQELEMS YIRIFTKILM QFLINSKDKL RVMLNFS