The formation of a complex between the membrane structures of the mitochondria and DNA of nonmitochondrial origin.

The ability of decomposed rat liver mitochondria, stripped of their outer membrane (fracton C) to bind 14C-DNA of phage T4 was demonstrated. The bound phage DNA is 10-15% resistant to treatment of fraction C with DNAase I. Treatment of fraction C with sarcosyl (final concentration 0.1%) and centrifugation in a linear sucrose gradient (20-50%) permits the detection of a label in the Mt-DNA-membrane complex, isolated at 35% sucrose. Further fractionation of the membrane complex on sepharose 4 B promotes the detection of the label in "elementary particles of transcription" [1], structural units of the inner membrane, containing specific centers for binding to DNA. The centers of binding of the elementary particles of transcription possess greatest affinity for Mt-DNA; however, they are also capable of binding DNA of various origin (both the DNA of eucaryotes and that of procaryotes). The significance of fixation of DNA of nonmitochondrial origin by the membrane structures of the mitochondria is discussed.