FIGURE 8.

Schematic comparing relative supercoiling set points of a select number of bacterial type IIA topoisomerases. topo IV relaxes DNA. E. coli gyrase can negatively supercoil DNA both rapidly and extensively. M. tuberculosis (Mtb) and S. typhimurium gyrase, as well as an E. coli gyrase lacking the C-terminal tail of the GyrA subunit, can all negatively supercoil DNA, but to a lesser degree than wild-type E. coli gyrase. Some of the mechanistic properties that appear to mediate these differences are listed at bottom.