A comparative structural analysis of sepiapterin reductase from Drosophila by homology modeling

Abstract

Sepiapterin reductase (SR) catalyzes the final steps of BH4 biosynthesis. Previously, a gene encoding SR has been cloned and characterized from a Drosophila cDNA library in vitro. The present study reports the identification of another SR gene in the Drosophila genome and the structural characteristics and differences of the two Drosophila SRs, using homology modeling analysis. Homology modeling of SRs for protein structure and function prediction showed that the two SRs have different surface electrostatic distributions and different shapes of the substrate (sepiapterin)-binding sites. These results provide valuable insight into the possibility of diverse functions of Drosophila SRs in vivo.

Keywords

• drosophila
• sepiapterin reductase
• structure
• tetrahydrobiopterin (bh4)