Above is the wild-type structure of the arc repressor showing the salt triad between R31, E36, and R40. The pdb can be downloaded here: [Bbk|BNL|ExP|Waw|Hal].

Above is the mutant structure of the arc repressor showing close hydrophobic packing between M31, Y36, and L40 (colours for clarity only). The pdb can be downloaded here: [Bbk|BNL|ExP|Waw|Hal] .

Salt Bridges