Erv1p from Saccharomyces cerevisiae is a FAD-linked sulfhydryl oxidase

The yeast ERV1 gene encodes a small polypeptide of 189 amino acids that is essential for mitochondrial function and for the viability of the cell. In this study we report the enzymatic activity of this protein as a flavin-lin ked sulfhydryl oxidase catalyzing the formation of disulfide bridges. Delet ion of the amino-terminal part of Erv1p shows that the enzyme activity is l ocated in the 15 kDa carboxy-terminal domain of the protein. This fragment of Erv1p still binds FAD and catalyzes the formation of disulfide bonds but is no longer able to form dimers like the complete protein. The carboxy-te rminal fragment contains a conserved CXXC motif that is present in all homo logous proteins from yeast to human. Thus Erv1p represents the first FAD-Li nked sulfhydryl oxidase from yeast and the first of these enzymes that is i nvolved in mitochondrial biogenesis. (C) 2000 Federation of European Bioche mical Societies. Published by Elsevier Science B.V. All rights reserved.