ID   HO1_SYNY3               Reviewed;         240 AA.
AC   P72849;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   04-NOV-2026, entry version 154.
DE   RecName: Full=Heme oxygenase 1 {ECO:0000303|PubMed:9744099};
DE            Short=HO1 {ECO:0000303|PubMed:9744099};
DE            Short=SynHO1 {ECO:0000303|PubMed:22992734};
DE            EC=1.14.14.18 {ECO:0000269|PubMed:9744099, ECO:0000305|PubMed:22992734};
GN   Name=ho1 {ECO:0000303|PubMed:8905231}; Synonyms=pbsA1;
GN   OrderedLocusNames=sll1184;
OS   Synechocystis sp. (strain ATCC 27184 / PCC 6803 / Kazusa).
OC   Bacteria; Bacillati; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC   Merismopediaceae; Synechocystis.
OX   NCBI_TaxID=1111708;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=8905231; DOI=10.1093/dnares/3.3.109;
RA   Kaneko T., Sato S., Kotani H., Tanaka A., Asamizu E., Nakamura Y.,
RA   Miyajima N., Hirosawa M., Sugiura M., Sasamoto S., Kimura T., Hosouchi T.,
RA   Matsuno A., Muraki A., Nakazaki N., Naruo K., Okumura S., Shimpo S.,
RA   Takeuchi C., Wada T., Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. II. Sequence determination of the entire
RT   genome and assignment of potential protein-coding regions.";
RL   DNA Res. 3:109-136(1996).
RN   [2]
RP   FUNCTION, CATALYTIC ACTIVITY, ACTIVITY REGULATION, SUBCELLULAR LOCATION,
RP   AND INDUCTION.
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=9744099; DOI=10.1046/j.1365-313x.1998.00186.x;
RA   Cornejo J., Willows R.D., Beale S.I.;
RT   "Phytobilin biosynthesis: cloning and expression of a gene encoding soluble
RT   ferredoxin-dependent heme oxygenase from Synechocystis sp. PCC 6803.";
RL   Plant J. 15:99-107(1998).
RN   [3]
RP   FUNCTION.
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=10949378; DOI=10.1023/a:1006489129449;
RA   Willows R.D., Mayer S.M., Foulk M.S., DeLong A., Hanson K., Chory J.,
RA   Beale S.I.;
RT   "Phytobilin biosynthesis: the Synechocystis sp. PCC 6803 heme oxygenase-
RT   encoding ho1 gene complements a phytochrome-deficient Arabidopsis thalianna
RT   hy1 mutant.";
RL   Plant Mol. Biol. 43:113-120(2000).
RN   [4]
RP   FUNCTION IN CHROMOPHORE SYNTHESIS.
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=16458890; DOI=10.1016/j.febslet.2006.01.051;
RA   Mukougawa K., Kanamoto H., Kobayashi T., Yokota A., Kohchi T.;
RT   "Metabolic engineering to produce phytochromes with phytochromobilin,
RT   phycocyanobilin, or phycoerythrobilin chromophore in Escherichia coli.";
RL   FEBS Lett. 580:1333-1338(2006).
RN   [5]
RP   FUNCTION, AND CATALYTIC ACTIVITY.
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=22992734; DOI=10.1074/jbc.m112.414078;
RA   Sigala P.A., Crowley J.R., Hsieh S., Henderson J.P., Goldberg D.E.;
RT   "Direct tests of enzymatic heme degradation by the malaria parasite
RT   Plasmodium falciparum.";
RL   J. Biol. Chem. 287:37793-37807(2012).
RN   [6] {ECO:0007744|PDB:1WE1}
RP   X-RAY CRYSTALLOGRAPHY IN COMPLEX WITH HEME, IRON-BINDING SITE, AND SUBUNIT.
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=15560792; DOI=10.1111/j.1432-1033.2004.04411.x;
RA   Sugishima M., Migita C.T., Zhang X., Yoshida T., Fukuyama K.;
RT   "Crystal structure of heme oxygenase-1 from cyanobacterium Synechocystis
RT   sp. PCC 6803 in complex with heme.";
RL   Eur. J. Biochem. 271:4517-4525(2004).
CC   -!- FUNCTION: Catalyzes the opening of a heme ring to form the open-chain
CC       tetrapyrrole biliverdin IXalpha with the release of iron and carbon
CC       monoxide (CO) (Probable) (PubMed:22992734). Key enzyme in the synthesis
CC       of the chromophoric part of the photosynthetic antennae (Probable).
CC       Requires reduced ferredoxin (PubMed:9744099). Complements an HO1
CC       disruption in A.thaliana (PubMed:10949378). Coexpression of
CC       phycocyanobilin:ferredoxin oxidoreductase (pcyA) and HO1 in E.coli
CC       leads to synthesis of phycocyanobilin (PubMed:16458890). Coexpression
CC       in E.coli with PebB and PebA (from Synechococcus strain WH8020) and
CC       Cph1 (from Synechocystis residues 1-514, as acceptor) leads to covalent
CC       attachment of a probable phycoerythrobilin chromophore to Cph1
CC       (PubMed:16458890). {ECO:0000269|PubMed:10949378,
CC       ECO:0000269|PubMed:16458890, ECO:0000269|PubMed:22992734,
CC       ECO:0000269|PubMed:9744099, ECO:0000305|PubMed:9744099}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=heme b + 3 reduced [NADPH--hemoprotein reductase] + 3 O2 =
CC         biliverdin IXalpha + CO + Fe(2+) + 3 oxidized [NADPH--hemoprotein
CC         reductase] + 3 H2O + H(+); Xref=Rhea:RHEA:21764, Rhea:RHEA-
CC         COMP:11964, Rhea:RHEA-COMP:11965, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:15379, ChEBI:CHEBI:17245,
CC         ChEBI:CHEBI:29033, ChEBI:CHEBI:57618, ChEBI:CHEBI:57991,
CC         ChEBI:CHEBI:58210, ChEBI:CHEBI:60344; EC=1.14.14.18;
CC         Evidence={ECO:0000269|PubMed:9744099, ECO:0000305|PubMed:22992734};
CC   -!- ACTIVITY REGULATION: Irreversibly inactivated by Ni(2+); about 25%
CC       inhibited by Sn-protoporphyrin IX (a potent inhibitor of animal HO
CC       enzymes). {ECO:0000269|PubMed:9744099}.
CC   -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:15560792}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:9744099}.
CC   -!- INDUCTION: Transcribed at low levels in growing cells, transcription is
CC       further induced in iron-deficient medium. {ECO:0000269|PubMed:9744099}.
CC   -!- MISCELLANEOUS: E.coli cells expressing this gene turn pale green due to
CC       accumulation of biliverdin IX-alpha. {ECO:0000269|PubMed:16458890,
CC       ECO:0000269|PubMed:9744099}.
CC   -!- SIMILARITY: Belongs to the heme oxygenase family. {ECO:0000305}.
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DR   EMBL; BA000022; BAA16864.1; -; Genomic_DNA.
DR   PIR; S74713; S74713.
DR   PDB; 1WE1; X-ray; 2.50 A; A/B/C/D=1-240.
DR   AlphaFoldDB; P72849; -.
DR   SMR; P72849; -.
DR   IntAct; P72849; 2.
DR   STRING; 1148.gene:10497722; -.
DR   PaxDb; 1148-gene:10497722; -.
DR   EnsemblBacteria; BAA16864; BAA16864; BAA16864.
DR   KEGG; syn:sll1184; -.
DR   eggNOG; COG5398; Bacteria.
DR   InParanoid; P72849; -.
DR   OMA; AADMAYW; -.
DR   PhylomeDB; P72849; -.
DR   BioCyc; MetaCyc:MONOMER-13860; -.
DR   BRENDA; 1.14.14.18; 6192.
DR   BRENDA; 1.14.15.20; 382.
DR   EvolutionaryTrace; P72849; -.
DR   Proteomes; UP000001425; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005886; C:plasma membrane; IBA:GO_Central.
DR   GO; GO:0020037; F:heme binding; IBA:GO_Central.
DR   GO; GO:0004392; F:heme oxygenase (decyclizing) activity; IBA:GO_Central.
DR   GO; GO:0042167; P:heme catabolic process; IBA:GO_Central.
DR   GO; GO:0006788; P:heme oxidation; IBA:GO_Central.
DR   GO; GO:0006979; P:response to oxidative stress; IBA:GO_Central.
DR   CDD; cd19165; HemeO; 1.
DR   FunFam; 1.20.910.10:FF:000001; Heme oxygenase 1; 1.
DR   Gene3D; 1.20.910.10; Heme oxygenase-like; 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; HEME OXYGENASE; 1.
DR   PANTHER; PTHR10720:SF0; HEME OXYGENASE; 1.
DR   Pfam; PF01126; Heme_oxygenase; 1.
DR   PIRSF; PIRSF000343; Haem_Oase; 1.
DR   PRINTS; PR00088; HAEMOXYGNASE.
DR   SUPFAM; SSF48613; Heme oxygenase-like; 1.
DR   PROSITE; PS00593; HEME_OXYGENASE; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Cytoplasm; Heme; Iron; Metal-binding; Oxidoreductase;
KW   Photosynthesis; Reference proteome.
FT   CHAIN           1..240
FT                   /note="Heme oxygenase 1"
FT                   /id="PRO_0000209701"
FT   BINDING         10
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /evidence="ECO:0000269|PubMed:15560792,
FT                   ECO:0007744|PDB:1WE1"
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:0000269|PubMed:15560792,
FT                   ECO:0007744|PDB:1WE1"
FT   BINDING         125
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /evidence="ECO:0000269|PubMed:15560792,
FT                   ECO:0007744|PDB:1WE1"
FT   BINDING         168
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /evidence="ECO:0000269|PubMed:15560792,
FT                   ECO:0007744|PDB:1WE1"
FT   BINDING         172
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /evidence="ECO:0000269|PubMed:15560792,
FT                   ECO:0007744|PDB:1WE1"
FT   HELIX           5..12
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           14..21
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           24..30
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           36..59
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   TURN            60..62
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           66..69
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           77..88
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           92..95
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           100..115
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           117..119
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           120..124
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           125..129
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           130..146
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   STRAND          149..152
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           154..156
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           164..176
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           182..205
FT                   /evidence="ECO:0007829|PDB:1WE1"
FT   HELIX           207..222
FT                   /evidence="ECO:0007829|PDB:1WE1"
SQ   SEQUENCE   240 AA;  27051 MW;  7F17A033768BAFA8 CRC64;
     MSVNLASQLR EGTKKSHSMA ENVGFVKCFL KGVVEKNSYR KLVGNLYFVY SAMEEEMAKF
     KDHPILSHIY FPELNRKQSL EQDLQFYYGS NWRQEVKISA AGQAYVDRVR QVAATAPELL
     VAHSYTRYLG DLSGGQILKK IAQNAMNLHD GGTAFYEFAD IDDEKAFKNT YRQAMNDLPI
     DQATAERIVD EANDAFAMNM KMFNELEGNL IKAIGIMVFN SLTRRRSQGS TEVGLATSEG
//