FIGURE 5.

Theoretical genomic photoreactivity based on bipyrimidine signature (P_g) vs. G+C content (%) of 29 halophilic archaea and 243 other prokaryotic genomes (adapted from Jones and Baxter, 2016). P_g is calculated as the weighted sum of a genome’s bipyrimidine incidences: P_g = 1.73(TC_i) + 1.19(TT_i) + 0.61(CT_i) + 0.39(CC_i). Bipyrimidine incidence corresponds to bipyrimidine frequency divided by genome size. Weighting coefficients represent the intrinsic photoreactivity of each bipyrimidine sequence, determined experimentally by Matallana-Surget et al. (2008) as the ratio between the frequency of photoproducts (CPDs and (6-4)PPs) and bipyrimidine incidences in DNA with varying G+C content.