Cell-free synthesis of ubiquinone-binding protein of mitochondrial cytochrome bc1 complex

In vitro synthesis of the ubiquinone-binding protein of mitochondrial cytochrome bc1 complex has been studied. In vitro translation of rat liver poly(A)+ RNA followed by immunoprecipitation with antibody directed against bovine ubiquinone-binding protein yielded a polypeptide with a molecular weight that was the same as that of the mature protein. It was also found that this polypeptide was imported into mitochondria and became resistant to trypsin treatment, and that the import required the energized state of the inner membrane.