Figure 4

Deviations are observed in the disposition of the β-binding motif. The clamps are shown in surface form and the peptides in stick representation, with atomic colouring. Complexes shown are: Pol II [PDB:3D1E], Pol III [PDB:3D1F], Pol IV [PDB:1UNN] and Pol V/UmuC [this study] [7, 14]. Individual figures derive from superimposed structures to yield a view of the entire binding pocket in the same orientation in each instance, with the N-terminus of the peptides to the left of the view and the C-terminus to the right.