Reaction: (1) 7,8-dihydrobiopterin + NADP+ = sepiapterin + NADPH + H+
(2) tetrahydrobiopterin + 2 NADP+ = 6-pyruvoyl-5,6,7,8-tetrahydropterin + 2 NADPH + 2 H+
For diagram of reaction click here.
Other name(s): SR
Systematic name: 7,8-dihydrobiopterin:NADP+ oxidoreductase
Comments: This enzyme catalyses the final step in the de novo synthesis of tetrahydrobiopterin from GTP, with the other enzymes involved being EC 3.5.4.16 (GTP cyclohydrolase I) and EC 4.2.3.12 (6-pyruvoyltetrahydropterin synthase) [5].
Links to other databases: BRENDA, EXPASY, GTD, KEGG, PDB, CAS registry number: 9059-48-7
References:
1. Katoh, S. Sepiapterin reductase from horse liver: purification and properties of the enzyme. Arch. Biochem. Biophys. 146 (1971) 202-214. [PMID: 4401291]
2. Matsubara, M., Katoh, S., Akino, M. and Kaufman, S. Sepiapterin reductase. Biochim. Biophys. Acta 122 (1966) 202-212. [PMID: 5969298]
3. Werner, E.R., Schmid, M., Werner-Felmayer, G., Mayer, B. and Wachter, H. Synthesis and characterization of 3H-labelled tetrahydrobiopterin. Biochem. J. 304 (1994) 189-193. [PMID: 7528005]
4. Kim, Y.A., Chung, H.J., Kim, Y.J., Choi, Y.K., Hwang, Y.K., Lee, S.W. and Park, Y.S. Characterization of recombinant Dictyostelium discoideum sepiapterin reductase expressed in E. coli. Mol. Cells 10 (2000) 405-410. [PMID: 10987137]
5. Supangat, S., Choi, Y.K., Park, Y.S., Son, D., Han, C.D. and Lee, K.H. Expression, purification, crystallization and preliminary X-ray analysis of sepiapterin reductase from Chlorobium tepidum. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 61:202 (2005). [PMID: 16510994]
6. Choi, Y.K., Jun, S.0R., Cha, E.-Y., Park, J.S. and Park, Y.S. Sepiapterin reductases from Chlorobium tepidum and Chlorobium limicola catalyze the synthesis of L-threo-tetrahydrobiopterin from 6-pyruvoyltetrahydropterin. FEMS Microbiol. Lett. 242 (2005) 95-99. [PMID: 15621425]