Mouse sepiapterin reductase: an enzyme involved in the final step of tetrahydrobiopterin biosynthesis. Primary structure deduced from the cDNA sequence.

We carried out the cloning of a mouse cDNA encoding a sepiapterin reductase which is involved in the final step of tetrahydrobiopterin biosynthesis as a first step toward gene-targeting technique in mice. The sequence contained 1245 nucleotides consisting of an open reading frame of 783 nucleotides encoding a protein of 261 amino acid residues whose molecular weight was 27,851, a 5'-untranslated region of 21 nucleotides and a 3'-untranslated region of 441 nucleotides containing poly(A) tail. The amino acid sequence of mouse sepiapterin reductase revealed the identity of 88% with rat and 74% with human sequence.