Sepiapterin reductase

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
Search PMC articles PubMed articles

In enzymology, a sepiapterin reductase (SPR) (EC 1.1.1.153) is an enzyme that catalyzes the following chemical reaction:

7,8-dihydrobiopterin + NADPH + H⁺ $\rightleftharpoons$ tetrahydrobiopterin + NADP⁺

Thus, the two substrates of this enzyme are 7,8-dihydrobiopterin (DHB, BH₂) and NADP⁺, whereas its three products are tetrahydrobiopterin (THB, BH₄) or 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.

Structural Studies

As of late 2007, five structures have been solved for this class of enzymes, with Protein Data Bank (PDB) accession codes 1NAS, 1OAA, 1SEP, 1Z6Z, and 2BD0.

References

• Katoh S (1971). "Sepiapterin Reductase from Horse Liver: Purification and Properties of the Enzyme.". Arch. Biochem. Biophys. 146 (1): 202–214. doi:10.1016/S0003-9861(71)80057-7. PMID 4401291. 
• Matsubara M, Katoh S, Akino M, Kaufman S (1966). "Sepiapterin Reductase.". Biochim. Biophys. Acta. 122 (2): 202–212. PMID 5969298.