This diagram colours residues according to whether they are folded or unfolded in the transition state. Residues involved in interaction that are completely broken in the transition state are coloured blue, those involved in interactions that are completely formed in the transition state are coloured red, and intermediate transition state interactions are coloured as below.
Red Pink Magenta Purple Blue Broken <----------------------->Formed in TS in TS
Yellow indicates the sites of the engineered disulphide bridges. The bridge on the right (85 / 102) is in a region which is still partially formed in the TS, i.e. it breaks late on the unfolding pathway. The bridge on the left (43 / 80) is in a region that is completely broken in the TS.
Click here for the pdb of the wild-type structure: [Bbk|BNL|ExP|Waw|Hal].