Figure 2: EnvZ^chim structure.

(a) Overall structure of EnvZ^chim. Cartoon representation of the homodimeric EnvZ^chim structure (subunit A in cyan and subunit B in green) in two orthogonal views. The DHp region interchanged is highlighted in blue for subunit A and in orange for subunit B. ATP lid is coloured in magenta and the AMPPNP, sulphate (SO₄) and the phosphorylatable H243 are drawn as sticks. (b) Comparison of EnvZ^chim DHp with EnvZ and HK853. A cartoon representation, in cylindrical helices, for the DHp superimposition of homodimeric EnvZ^chim (one subunit in cyan and the other in blue) with EnvZ (3ZRW; one subunit in yellow and the other in orange) and HK853 (2C2A; one subunit in pink and the other in purple). In the homodimers, α-helices are labelled and phosphorylatable His are shown as sticks. Two orthogonal views, lateral and from the apex, are displayed. (c) EnvZ^chim structure shows asymmetry. Superposition of DHp from subunit A (cyan) and B (green) illustrates the asymmetry due to a rotational movement of CA in relation to DHp (55.6° calculated by Dyndom).