Molecular Cloning and Sequencing of ζ-Crystallin/Quinone Reductase cDNA from Human Liver

Zeta-crystallin is an enzyme-crystallin highly expressed in the lens of some hystricomorph rodents and camels. It has been shown to have a novel NADPH:quinone oxidoreductase activity and is present at enzymatic levels in a variety of tissues from various mammals. We report here the cDNA cloning of ζ-crystallin from a human liver library. One clone with the complete open reading frame was obtained. Ten nucleotides of the 5′ and 796 of the 3′ non-translated regions are present in the clone including two possible polyadenylation signals. The deduced amino acid sequence is 328 residues long with a calculated molecular mass of 34910 daltons and isoelectric point of 8.73. It shows 84% identity with the guinea pig protein.