(A) Two views of the dimeric Dip structure. Protomers are coloured in green and blue. (B) Electrostatic surface representation (red = negative, blue = positive) of the Dip dimer. The negatively charged, patch/pocket on the outer surface of the Dip-dimer is indicated with the dashed box. (C) The structural interaction between peptide 756–775 (of RNase E) and Dip. The in-silico docked peptide is shown as a red helix, and the peptide modelled from X-ray crystal data is shown as purple and blue sticks. (D) Experimental structure of the complex, showing a close view of the interacting amino acids of Dip (D137, D138, E214 and E222) and RNase E peptide 756–775. The electron density map is shown for the RNase E peptide only for clarity. (E) EMSA of wild type Dip and the mutant Dip-E214/E222 (substituted to Ala) and the RNase E peptides 583–636 and 725–901. The samples were run on an 8% native acrylamide gel. Concentrations are presented in µM.