CLONING, TISSUE EXPRESSION, AND MAPPING OF A HUMAN PHOTOLYASE HOMOLOGWITH SIMILARITY TO PLANT BLUE-LIGHT RECEPTORS

Enzymatic photoreactivation is a DNA repair mechanism that removes UV- induced pyrimidine dimer lesions by action of a single enzyme, photoly ase, and visible light. Its presence has been demonstrated in a wide v ariety of organisms, ranging from simple prokaryotes to higher eukaryo tes. We have isolated a human gene encoding a 66-kDa protein that show s clear overall homology to known bacterial photolyase genes. The huma n gene product is more similar to plant blue-light receptors within cl ass I photolyases than to higher eukaryote class II photolyases. North ern blot analysis showed two transcripts with constitutive expression in all tissues examined and an elevated expression in testis. lit situ hybridization with a cDNA-derived probe localized this human gene to chromosome 12q23-q24.1. Southern analysis of the cloned human gene sug gests a wide distribution of the gene family in various species. (C) 1 996 Academic Press, Inc.