Sepiapterin reductase

Sepiapterin reductase (7,8-dihydrobiopterin:NADP+ oxidoreductase)

PDB rendering based on 1z6z.
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols SPR ; SDR38C1
External IDs OMIM: 182125 MGI: 103078 HomoloGene: 37735 GeneCards: SPR Gene
EC number 1.1.1.153
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez 6697 20751
Ensembl ENSG00000116096 ENSMUSG00000033735
UniProt P35270 Q91XH5
RefSeq (mRNA) NM_003124 NM_011467
RefSeq (protein) NP_003115 NP_035597
Location (UCSC) Chr 2:
72.89 – 72.89 Mb
Chr 6:
85.13 – 85.14 Mb
PubMed search

Sepiapterin reductase is an enzyme that in humans is encoded by the SPR gene.[1][2][3]

Function

Sepiapterin reductase (7,8-dihydrobiopterin:NADP+ oxidoreductase; EC 1.1.1.153) catalyzes the NADPH-dependent reduction of various carbonyl substances, including derivatives of pteridines, and belongs to a group of enzymes called aldo-keto reductases. SPR plays an important role in the biosynthesis of tetrahydrobiopterin.[3]

Reaction

sepiapterin reductase
Identifiers
EC number 1.1.1.153
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Gene Ontology AmiGO / EGO

Sepiapterin reductase (SPR) catalyzes the chemical reaction

L-erythro-7,8-dihydrobiopterin + NADP+ \rightleftharpoons sepiapterin + NADPH + H+

Thus, the two substrates of this enzyme are L-erythro-7,8-dihydrobiopterin and NADP+, whereas its three products are sepiapterin, NADPH, and a single hydrogen ion (H+).

This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 7,8-dihydrobiopterin:NADP+ oxidoreductase. This enzyme participates in folate biosynthesis.

[4]

Clinical significance

Sepiapterin reductase deficiency belongs to the rare diseases. The clinical phenotype can include progressive psychomotor retardation, altered tone, seizures, choreoathetosis, temperature instability, hypersalivation, microcephaly, and irritability. Patients with sepiapterin reductase deficiency also manifest dystonia with diurnal variation, oculogyric crises, tremor, hypersomnolence, oculomotor apraxia, and weakness. [5] Response to treatment is variable and the long-term and functional outcome is unknown. To provide a basis for improving the understanding of the epidemiology, genotype/phenotype correlation and outcome of these diseases their impact on the quality of life of patients, and for evaluating diagnostic and therapeutic strategies a patient registry was established by the noncommercial International Working Group on Neurotransmitter Related Disorders (iNTD). [6]


References

  1. Ichinose H, Katoh S, Sueoka T, Titani K, Fujita K, Nagatsu T (Oct 1991). "Cloning and sequencing of cDNA encoding human sepiapterin reductase--an enzyme involved in tetrahydrobiopterin biosynthesis". Biochem Biophys Res Commun 179 (1): 183–189. doi:10.1016/0006-291X(91)91352-D. PMID 1883349.
  2. Persson B, Kallberg Y, Bray JE, Bruford E, Dellaporta SL, Favia AD, Duarte RG, Jornvall H, Kavanagh KL, Kedishvili N, Kisiela M, Maser E, Mindnich R, Orchard S, Penning TM, Thornton JM, Adamski J, Oppermann U (Feb 2009). "The SDR (short-chain dehydrogenase/reductase and related enzymes) nomenclature initiative". Chem Biol Interact 178 (1–3): 94–98. doi:10.1016/j.cbi.2008.10.040. PMC 2896744. PMID 19027726.
  3. 1 2 "Entrez Gene: SPR sepiapterin reductase (7,8-dihydrobiopterin:NADP+ oxidoreductase)".
  4. http://brenda-enzymes.info/enzyme.php?ecno=1.1.1.153
  5. Pearl PL, Taylor JL, Trzcinski S, Sokohl A (May 2007). "The pediatric neurotransmitter disorders". J Child Neurol 22 (5): 606–616. PMID 17690069.
  6. "Patient registry".

Further reading

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