AbstractThe insert‐containing, non‐canonicalori 6region of yeast mitochrondrial DNA ofSaccharomyces cerevisiaewas dissected into 15 different segments that were ligated to the integrative yeast vector YIp5. Six recombinant plasmids exhibited replicative ability in yeast and carried consensus sequences similar to the previously described 11 bp motifs active as autonomous replication sequences (ARS). In addition, all active constructions carry one or more of the characteristic GC‐rich domains A, B or C present in theori 6region, thus confirming and expanding the study of Blanc (Gene30(1984) 47–61) with the canonicalori 5. Also a new transcriptional origin is activated in theori 6region, apparently circumventing a disruption by insertion of a GC‐rich sequence that, in thisori, removes the mitochondrial promoter usually present next to the Celement. The ARS‐positive constructions correspond to the retained segments of spontaneous well‐characterized suppressive or neutral petite genomes that contain segments of t