Fig. 2.

a Model for supercoil density control based a branch point leading to DNA dissociation (D) or processive reactions (P) where the enzyme remains bound to the same site. ΔLk Linking number change, Pi inorganic phosphorus, Mu SGS strong DNA gyrase cleavage site at the center of the Mu genome, CTD C-terminal domain. b Comparison of the C-terminal acidic tails of E. coli (E.c.) and Salmonella Typhimurium (S.T.) Acidic tail residues are shown in red