Structural comparisons and domain interactions in LdtMt2Δ130. (a) A superposition of the four chains in the three LdtMt2Δ130 models and a plot of the Cα r.m.s. deviations between any pair of chains averaged over the six pairwise comparisons. The apo, mercury-derivatized and meropenem-complexed LdtMt2 (chains A and B) are coloured orange, magenta, yellow and blue, respectively. (b) Interactions between the C-terminal tail and two domains coloured as in Fig. 1(a). The enlarged views on the left have slightly different orientations in order to show the detailed interactions better.