Southern blot analysis of DNA treated with Topoisomerase IV.

<p>The filter contains pooled CsCl fractions of <i>K. veneficum</i> DNA, undigested (−), treated with Topoisomerase IV (To), and digested with EcoRI (E). The hybridization probe is identical to probe 4 of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038809#pone-0038809-g003" target="_blank">Figure 3</a>, containing the highly conserved motif 2 and a partial sequence of motif 1. The location of the plastid genome is indicated by green shade above the lanes.</p>