Fig. 5. AimR^Kat DNA-binding characterisation.

a Overall structure of AimR^Kat in complex with DNA. Two orthogonal views are shown. Subunits A and B are represented in cartoon with helices as cylinders and coloured in brown and magenta respectively. DNA is painted in orange and yellow for 5′-3′and 3′-5′ strands, respectively. Darker colours have been used for DNA interacting regions with helix α3 shown with a bigger radius and DNA interacting residues represented in stick. b Overall superposition of AimR^Kat (same colour code as for a) and AimR^SPβ (coloured in blue). DNA is shown as yellow cartoon and surface for AimR^Kat and blue surface for AimR^SPβ. c Detail view of DNA specific recognition mediated by helix α3 in AimR^Kat (coloured in magenta) and AimR^SPβ (semi-transparent and coloured in blue). Interacting residues are shown in sticks and labelled. d Schematic representation of the DNA-AimR^Kat contacts. The colour code is the same as for (a). Sequence-specific interactions for DNA readout are highlighted with thicker lines and the residues carrying out these interactions with more intense colours.