Fig. 7.

Phylogenetic tree of archaeal Top6A and Top6B orthologs. Selected sequences (n = 35) from DNA gyrase-less (red) and DNA gyrase-encoding (black) organisms were aligned using T-Coffee and non-homologous positions were removed using BMGE. The final alignment contained 420 positions for Top6B subunit and 332 positions for Top6A subunit. Maximum likelihood trees were constructed using IQ-tree with LG + F+I + G4 and LG + I+G4 sequence evolution models for Top6B and Top6A, respectively. Clades corresponding to four archaeal superphyla are indicated, note that Euryarchaeota was split into group I and group II Euryarchaeota as defined by Forterre et al. (2014).