Fig 1.

Titration of Tp34 with metal ions in solution. (A) c(s) distributions of Tp34 sedimented in the absence or presence of different total concentrations of Ni²⁺. The [Ni²⁺]_total values for the four experiments were 0 nM (black line), 25 nM (red line), 40 μM (blue line), and 1.6 mM (green line). (B) Binding isotherms for four metal ions. The circles represent individual data points, while the lines are fits to those data as described in the text. Data for Cu²⁺ (blue inverted triangles and line), Zn²⁺ (black circles and line), Co²⁺ (magenta triangles and line), and Ni²⁺ (green squares and line) are shown.