Replication of mitochondrial DNA. Selective inhibition of the H-strand synthesis in isolated mitochondria by sibiromycin.

Sibiromycin, an antitumour antibiotic forming a stable complex with the double-stranded DNA selectively inhibits the incorporation of [3H]thymidine into the H-strand of mtDNA during the incubation of isolated rat liver mitochondria in vitro. A model accounting for this result is presented. It is concluded that the H-strand is a leading strand throughout mtDNA replication adn consequently the replication of rat liver monomer mtDNA is unidirectional.