Topo mutants psoralen photobinding

We present a DNA array-based method for the genome-wide analysis of Psoralen photobinding in Saccharomyces cerevisiae cells. PB was found reduced in subtelomeric regions and increased in the subset of genes with smallest nucleosomal density. The analysis includes 3 repeats of the wild type strain (JCW25) at 30ºC and 3 more at 37ºC, 3 repeats of the double top1 (delta) top2ts mutant at 37ºC and 3 repeats of naked genomic DNA treated with trimethyl psoralen (TMP) in the same way to be used as a control of unspecific binding.