MGP Database

New search | Record Overview | Ontology/Pathway Information | Domain Information | UniProt Annotations | Related Proteins
MGP001462

UniProt Annotations

Entry Information
Gene Namehydroxymethylbilane synthase
Protein EntryHEM3_HUMAN
UniProt IDP08397
SpeciesHuman
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=4; Name=1; Synonyms=Non-erythropoietic; IsoId=P08397-1; Sequence=Displayed; Name=2; Synonyms=Erythrocyte; IsoId=P08397-2; Sequence=VSP_002067; Name=3; IsoId=P08397-3; Sequence=VSP_047294; Note=No experimental confirmation available.; Name=4; IsoId=P08397-4; Sequence=VSP_002067, VSP_047294; Note=No experimental confirmation available.;
Catalytic Activity4 porphobilinogen + H(2)O = hydroxymethylbilane + 4 NH(3).
CofactorName=dipyrromethane; Xref=ChEBI:CHEBI:60342; Note=Binds 1 dipyrromethane group covalently.;
DiseaseAcute intermittent porphyria (AIP) [MIM:176000]: A form of porphyria. Porphyrias are inherited defects in the biosynthesis of heme, resulting in the accumulation and increased excretion of porphyrins or porphyrin precursors. They are classified as erythropoietic or hepatic, depending on whether the enzyme deficiency occurs in red blood cells or in the liver. AIP is an autosomal dominant form of hepatic porphyria characterized by attacks of gastrointestinal disturbances, abdominal colic, with neurological dysfunctions, hypertension, tachycardia and peripheral neuropathy. Most attacks are precipitated by drugs, alcohol, caloric deprivation, infections, or endocrine factors. {ECO:0000269|PubMed:10453740, ECO:0000269|PubMed:10494093, ECO:0000269|PubMed:10502788, ECO:0000269|PubMed:10602775, ECO:0000269|PubMed:10657149, ECO:0000269|PubMed:10782018, ECO:0000269|PubMed:11013452, ECO:0000269|PubMed:11030413, ECO:0000269|PubMed:11399210, ECO:0000269|PubMed:11857754, ECO:0000269|PubMed:12372055, ECO:0000269|PubMed:12406973, ECO:0000269|PubMed:1301948, ECO:0000269|PubMed:1427766, ECO:0000269|PubMed:14669009, ECO:0000269|PubMed:1496994, ECO:0000269|PubMed:14970743, ECO:0000269|PubMed:15669678, ECO:0000269|PubMed:1714233, ECO:0000269|PubMed:2243128, ECO:0000269|PubMed:7757070, ECO:0000269|PubMed:7962538, ECO:0000269|PubMed:8081367, ECO:0000269|PubMed:8262523, ECO:0000269|PubMed:8268934, ECO:0000269|PubMed:8270254, ECO:0000269|PubMed:8270256, ECO:0000269|PubMed:8401516, ECO:0000269|PubMed:8825929, ECO:0000269|PubMed:9199558, ECO:0000269|PubMed:9225970, ECO:0000269|PubMed:9463797, ECO:0000269|PubMed:9654202, ECO:0000269|Ref.44}. Note=The disease is caused by mutations affecting the gene represented in this entry.
FunctionTetrapolymerization of the monopyrrole PBG into the hydroxymethylbilane pre-uroporphyrinogen in several discrete steps.
MiscellaneousThe porphobilinogen subunits are added to the dipyrromethane group.
PathwayPorphyrin-containing compound metabolism; protoporphyrin- IX biosynthesis; coproporphyrinogen-III from 5-aminolevulinate: step 2/4.
SimilarityBelongs to the HMBS family. {ECO:0000305}.
Subcellular LocationCytoplasm {ECO:0000305}.
Tissue SpecificityIsoform 1 is ubiquitously expressed. Isoform 2 is found only in erythroid cells. {ECO:0000269|PubMed:3422427}.
  logo