Translation in Escherichia coli mini-cells containing hamster mitochondrial DNA-Co1E1 - Ampr recombinant plasmids

Abstract

Hamster mitochondrial DNA is cleaved into two fragments (4.2 and 11.4 kilobase pairs of DNA (kb)) by the restriction enzyme, Eco RI. Recombinant DNA molecules formed in vitro between an Escherichia coli plasmid, Co1E1 - Ampr, and Eco RI-digested hamster mitochondrial DNA were transformed into E. coli K12. The translation products of the parent plasmid, Co1E1 - Ampr, and recombinant plasmid DNAs containing (i) the 4.2 kb mitochondrial DNA fragment and (ii) the 11.4 kb fragment were characterized on sodium dodecyl sulfate-polyacrylamide gels using bacterial mini-cell lysates. The Co1E1 - Ampr plasmid specifies at least six polypeptides whose structural genes comprise 56% of the plasmid DNA. Insertion of hamster mitochondrial DNA at the Eco RI site of the plasmid alters the relative rate of synthesis of these six polypeptides and induces the occurrence of a new band on sodium dodecyl sulfate-polyacrylamide gels which is probably not specified by the inserted mitochondrial DNA sequences.