Cloning of the human RoDH-related short chain dehydrogenase gene and analysis of its structure

We have previously characterized the first human NAD(+)-dependent short cha in dehydrogenase capable of oxidizing all-trans-retinol and androgens, and found only in the liver and skin. In a search for related human enzymes, we identified a partial open reading frame, which exhibited > 60% sequence id entity to human RoDH-4. The full-length cDNA for this enzyme was determined in our laboratory by 5'-RACE PCR and was found to be identical to the rece ntly reported novel type of oxidative human 3 alpha -hydroxysteroid dehydro genase (3 alpha -HSD). Analysis of the genomic structure revealed that the gene for RoDH-like 3 alpha -HSD has four translated exons and, possibly, a fifth, exon that codes for the 5'-untranslated region. The gene for RoDH-4 appears to have only four exons. The positions of exon-intron boundaries an d the sizes of the protein coding regions are identical in 3 alpha -HSD and RoDH-4. Moreover, both genes are mapped to chromosome 12q13, and are locat ed in a close proximity to each other. Both genes appear to have satellite pseudogenes. Thus, RoDH-4 and 3 alpha -HSD genes share similar structural o rganization and cluster on human chromosome 12, near the gene for 11-cis re tinol dehydrogenase. (C) 2001 Elsevier Science Ireland Ltd. All rights rese rved.