Fig. 6
From: An affinity-structure database of helix-turn-helix: DNA complexes with a universal coordinate system
Canonical matching regions. Canonical matching regions are contiguous stretches of DNA in close proximity to the recognition helix. a To establish a canonical matching region, the DNA basepair position closest to the central residue of the recognition helix is identified (designated “n”). A schematic representation of all residue positions is shown on the right. b Multiple canonical matching regions, spanning five basepairs and constrained to include the nth DNA basepair position, are shown in pink highlights. The range of positions spanned by each region is shown in brackets under each respective complex, and depicted schematically on the right