Structural superposition of the DNA-binding domain of the Tma SSB and Eco SSB. Two views of superposition of Tma SSB (red) and Eco SSB (blue) rotated against each others to visualized salt bridge and flexible loop. The superposition indicates a structurally conserved core with flexible loops. (A) The discussed salt bridge Tma SSB protein between Asp108 (red) and Arg12 (light blue) and Arg73 (light blue). (B) The additional flexible loop of Eco SSB (yellow). Structures prepared with using VMD version 1.8.7 .