ID   MYG_ONDZI               Reviewed;         154 AA.
AC   P32428;
DT   01-OCT-1993, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   27-MAR-2024, entry version 78.
DE   RecName: Full=Myoglobin;
DE   AltName: Full=Nitrite reductase MB {ECO:0000250|UniProtKB:P02144};
DE            EC=1.7.-.- {ECO:0000250|UniProtKB:P02144};
DE   AltName: Full=Pseudoperoxidase MB {ECO:0000250|UniProtKB:P02144};
DE            EC=1.11.1.- {ECO:0000250|UniProtKB:P02144};
GN   Name=MB;
OS   Ondatra zibethicus (Muskrat).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea;
OC   Cricetidae; Arvicolinae; Ondatra.
OX   NCBI_TaxID=10060;
RN   [1]
RP   PROTEIN SEQUENCE OF 2-154.
RX   PubMed=2675985;
RA   Sukhomlinov B.F., Vasil'eva V.A.;
RT   "Amino acid sequence of muskrat (Ondatra zibethica) myoglobin.
RT   Characteristic features of the myoglobins of animals leading a semiaquatic
RT   way of life.";
RL   Biokhimiia 54:956-964(1989).
CC   -!- FUNCTION: Monomeric heme protein which primary function is to store
CC       oxygen and facilitate its diffusion within muscle tissues. Reversibly
CC       binds oxygen through a pentacoordinated heme iron and enables its
CC       timely and efficient release as needed during periods of heightened
CC       demand. Depending on the oxidative conditions of tissues and cells, and
CC       in addition to its ability to bind oxygen, it also has a nitrite
CC       reductase activity whereby it regulates the production of bioactive
CC       nitric oxide. Under stress conditions, like hypoxia and anoxia, it also
CC       protects cells against reactive oxygen species thanks to its
CC       pseudoperoxidase activity. {ECO:0000250|UniProtKB:P02144}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Fe(III)-heme b-[protein] + H2O + nitric oxide = Fe(II)-heme b-
CC         [protein] + 2 H(+) + nitrite; Xref=Rhea:RHEA:77711, Rhea:RHEA-
CC         COMP:18975, Rhea:RHEA-COMP:18976, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:16301, ChEBI:CHEBI:16480,
CC         ChEBI:CHEBI:55376, ChEBI:CHEBI:60344;
CC         Evidence={ECO:0000250|UniProtKB:P02144};
CC       PhysiologicalDirection=right-to-left; Xref=Rhea:RHEA:77713;
CC         Evidence={ECO:0000250|UniProtKB:P02144};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=AH2 + H2O2 = A + 2 H2O; Xref=Rhea:RHEA:30275,
CC         ChEBI:CHEBI:13193, ChEBI:CHEBI:15377, ChEBI:CHEBI:16240,
CC         ChEBI:CHEBI:17499; Evidence={ECO:0000250|UniProtKB:P02144};
CC   -!- SUBUNIT: Monomeric. {ECO:0000250|UniProtKB:P02185}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm, sarcoplasm
CC       {ECO:0000250|UniProtKB:P02144}.
CC   -!- SIMILARITY: Belongs to the globin family. {ECO:0000255|PROSITE-
CC       ProRule:PRU00238}.
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DR   PIR; PN0126; PN0126.
DR   GO; GO:0016528; C:sarcoplasm; ISS:UniProtKB.
DR   GO; GO:0020037; F:heme binding; IEA:InterPro.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0098809; F:nitrite reductase activity; ISS:UniProtKB.
DR   GO; GO:0019825; F:oxygen binding; IEA:InterPro.
DR   GO; GO:0005344; F:oxygen carrier activity; ISS:UniProtKB.
DR   GO; GO:0004601; F:peroxidase activity; ISS:UniProtKB.
DR   GO; GO:0019430; P:removal of superoxide radicals; ISS:UniProtKB.
DR   CDD; cd08926; Mb; 1.
DR   Gene3D; 6.10.140.2100; -; 1.
DR   Gene3D; 6.10.140.2110; -; 1.
DR   InterPro; IPR000971; Globin.
DR   InterPro; IPR009050; Globin-like_sf.
DR   InterPro; IPR002335; Myoglobin.
DR   PANTHER; PTHR47132; MYOGLOBIN; 1.
DR   PANTHER; PTHR47132:SF1; MYOGLOBIN; 1.
DR   Pfam; PF00042; Globin; 1.
DR   PRINTS; PR00613; MYOGLOBIN.
DR   SUPFAM; SSF46458; Globin-like; 1.
DR   PROSITE; PS01033; GLOBIN; 1.
PE   1: Evidence at protein level;
KW   Cytoplasm; Direct protein sequencing; Heme; Iron; Metal-binding;
KW   Muscle protein; Oxidoreductase; Oxygen transport; Phosphoprotein;
KW   Transport.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000269|PubMed:2675985"
FT   CHAIN           2..154
FT                   /note="Myoglobin"
FT                   /id="PRO_0000053323"
FT   BINDING         65
FT                   /ligand="nitrite"
FT                   /ligand_id="ChEBI:CHEBI:16301"
FT                   /evidence="ECO:0000250|UniProtKB:P68082"
FT   BINDING         65
FT                   /ligand="O2"
FT                   /ligand_id="ChEBI:CHEBI:15379"
FT                   /evidence="ECO:0000250|UniProtKB:P02189,
FT                   ECO:0000255|PROSITE-ProRule:PRU00238"
FT   BINDING         94
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="proximal binding residue"
FT                   /evidence="ECO:0000250|UniProtKB:P02144"
FT   MOD_RES         4
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0000250|UniProtKB:Q9QZ76"
FT   MOD_RES         68
FT                   /note="Phosphothreonine"
FT                   /evidence="ECO:0000250|UniProtKB:P04247"
SQ   SEQUENCE   154 AA;  17268 MW;  8C0CFF7E06651AE7 CRC64;
     MGLSDGEWQL VLHVWGKVEA DLAGHGQDVL IRLFKAHPET LEKFDKFKHI KSEDEMKGSE
     DLKKHGBTVL TALGGILKKK GHHEAEIKPL AQSHATKHKI PIKYLEFISE AIIHVLZSKH
     PSBFGADVZG AMKRALELFR NDIAAKYKEL GFQG
//