Figure 2.

His₅-tag-mediated crystal contacts. The central figure shows the overall structure of OcDH (green) with the His₅ tag (red) pointing into the cleft between the two domains of a symmetry-related molecule (white). Red circles indicate protein–protein-mediated crystal contacts and enlargements of these regions are shown on the left and right. The top of domain I interacts with the bottom of domain I of a neighbouring molecule. An identical arrangement is observed for domain II.