Cloning and sequencing of a cDNA encoding a copper-zinc superoxide dismutase enzyme from the marine yeast Debaryomyces hansenii
Résumé
Cu-Zn superoxide dismutase (SOD-1) is a ubiquitously occurring eukaryotic enzyme with a variety of important effects on respiring organisms. A gene (dhsod-1) encoding a Cu-Zn superoxide dismutase of the marine yeast Debaryomyces hansenii was cloned using mRNA by the RT-PCR technique. The deduced amino-acid sequence shows approximately 70% homology with that of cytosolic superoxide dismutase from Saccharomyces cerevisiae and Neurospora crassa, as well as lower homologies (between 55 and 65%) with the corresponding enzyme of other eukaryotic organisms, including human. The gene sequence encodes a protein of 153 amino acids with a calculated molecular mass of 15-92 kDa, in agreement with the observed characteristics of the purified protein from D. hansenii.