Interactions between the UmuC peptide and β-clamp. A. The clamp is coloured in gray and the peptide in magenta/atomic colouring. Interacting residues are depicted in stick representation with hydrogen bonds shown as black dotted lines. Key interacting residues from the β-clamp are labelled. B. Schematic of the peptide/clamp interactions. Backbone atoms are indicated by circles: Cα (white), C (gray), O (red) and N (blue) with side chains in line representation. Hydrogen bonds are indicated by dashed orange line with the indicated β-clamp residues. Proximal clamp residues are shown in blue under the respective peptide residue.