Promitochondria of Anaerobically Grown Yeast, V. Energy Transfer in the Absence of an Electron Transfer Chain

Abstract

Promitochondria of anaerobically grown Saccharomyces cerevisiae lack cytochromes aa ₃, b, c ₁, and c, as well as ubiquinone, yet catalyze a P_i-ATP exchange reaction that is sensitive to uncouplers, rutamycin, and atractyloside. The promitochondrial P_i-ATP exchange reaction is abolished by the cytoplasmic “petite” mutation, as well as by growth of the cells in the presence of erythromycin, which indicates a role of mitochondrial protein synthesis in the assembly of the energy transfer system. These observations demonstrate that mitochondrial energy transfer can occur in the absence of a respiratory chain.