The disulfide relay system of the mitochondrial intermembrane space has been extensively
characterized in Saccharomyces cerevisiae. It contains two essential components, Mia40
and Erv1. The genome of Arabidopsis thaliana contains a single gene for each of these
components. Although insertional inactivation of Erv1 leads to a lethal phenotype,
inactivation of Mia40 results in no detectable deleterious phenotype. A. thaliana Mia40 is
targeted to and accumulates in mitochondria and peroxisomes. Inactivation of Mia40 results …