DNA Catenation Reveals the Dynamics of DNA Topology During Replication
Two-dimensional agarose gel electrophoresis is the method of choice to identify and quantify all the topological forms DNA molecules can adopt in vivo. Here we describe the materials and protocols needed to analyze catenanes, the natural outcome of DNA replication, in Saccharomyces cerevisiae. We describe the formation of pre-catenanes during replication and how inhibition of topoisomerase 2 leads to the accumulation of intertwined sister duplexes. This knowledge is essential to determine how replication forks blockage or pausing affects the dynamic of DNA topology during replication.
Key wordsSaccharomyces cerevisiae Replication Supercoiling Catenation 2D gels
This work was supported by grant BFU2014-56835 from the Spanish Ministerio de Economía y Competitividad to JBS. We thank Jonathan Baxter and Luis Aragón for plasmids and DNA sequence data. The authors also acknowledge Alicia Rodríguez-Bernabé for technical help.