Figure 2
The crystal structures of apo- and H169T-DntR.
(a) The crystal structure of apo-DntR with subunits shown in different colours. The homotetramer adopts a configuration with a compact RD core. (b) The IBCs in the crystal structure of apo-DntR (stick representation) contain only ordered water molecules. Carbon atoms in purple, nitrogen atoms in blue and oxygen atoms in red. Water molecules are shown as red spheres. 2mFo-DFc, αcalc ‘omit’ electron density, contoured at the 1.4 x r.m.s. level, is shown as grey chicken wire. (c) Superposition of the apo-DntR IBC with that observed in the crystal structure of open-hinge salicylate-bound DntR RDs6 (yellow carbon atoms). (d) Superposition of the IBCs of apo-DntR and acetate-bound DntR5 (green carbon atoms). (e) The IBCs in the crystal structure of H169T-DntR (stick representation). Carbon atoms in purple, nitrogen atoms in blue and oxygen atoms in red. A thiocyanate ion bound in the IBC shown is labelled. 2mFo-DFc, αcalc ‘omit’ electron density, contoured at the 1.0 x r.m.s. level, is shown as grey chicken wire. (f) Superposition of the IBCs in the crystal structures of H169T-DntR and open-hinge salicylate-bound holo-DntR RDs6. (g) The results of flow cytometry measurements show that H169T-DntR autoinduces transcription albeit at a lower level than fully activated wild-type DntR.
