Figure 2.

Structural flexibility in the Vps75 dimer. Vps75 dimers from the asymmetrical and symmetrical forms of the Vps75 tetramer (dimers A and B respectively) along with previously solved crystal structures (PDB codes 3C9B (8) and 2ZD7 (9)) were aligned to chain A of the Vps75 dimer 3C9D (8). (A) In all instances the globular domains of the aligned monomers are well aligned but significant deviations are seen in the trajectory of the long dimerization helix, (B) this in turn causes the volume between the two globular domains of Vps75 monomers in the dimer to vary between crystal structures. The tetrameric dimers adopt a conformation most closely matched by the previously solved Vps75 dimer structure containing selenomethionine (3C9B), with a comparatively large volume between the two globular domains in the Vps75 dimer.