Figure 3.

2DNAGE analysis of S1 nuclease-resistant mtDNA RIs in cells induced to overexpress TFAM-stop. (a) Diagrammatic map of human mtDNA, nomenclature as for Figure 2a. (b–d) 2DNAGE of mtDNA from uninduced cells and from cells induced to express TFAM-stop for 48 h, analysed using the restriction digests and probes indicated. All samples were treated with S1 nuclease before electrophoresis. Nomenclature as for Figure 2, plus pr, pause region (replication slow-zone). See Supplementary Figure 5 for diagrammatic interpretations. Comparable exposures are shown, to illustrate the general enhancement of S1-resistant RIs, the strengthening of pause sites and regions and the decrease in termination intermediates. Note that bubble arcs are not visible at these exposures following S1 nuclease treatment.