GENOMIC ORGANIZATION AND CHROMOSOMAL LOCALIZATION OF THE HUMAN SEPIAPTERIN REDUCTASE GENE

Sepiapterin reductase (SPR) catalyzes the final step of the biosynthet ic pathway of tetrahydrobiopterin, which is an essential cofactor for aromatic amino acid hydroxylases and nitric oxide synthases. To aid th e analysis of any possible human diseases caused by mutations in SPR, we have cloned and characterized the human SPR gene. The gene is compo sed of three exons spanning approximately 4 kilobases. The transcripti onal starting point was determined around the cytosine nucleotide at p osition -81 by primer extension and RT-PCR analyses. There was no typi cal TATA-box within 300 bp from the transcriptional starting point. We found the Sp1-binding consensus sequence in the 5'-flanking region. T he human SPR gene was mapped to chromosome band 2p13 by fluorescence i n situ hybridization. (C) 1998 Academic Press.