(A) Intermolecular contacts between the little-finger domain (purple) and the template strand (cyan) in the preinsertion binary complex. The phosphate groups interacting with Dpo4 amino acids are highlighted by shaded spheres. The phosphate group of A9 of the template strand is circled for reference.
(B) Intermolecular contacts between the little-finger domain (purple) and the primer strand (green) in the preinsertion binary complex. The phosphate groups interacting with Dpo4 amino acids are highlighted by shaded spheres. The phosphate group of G6 of the primer strand is circled for reference.
(C) Intermolecular contacts between the little-finger domain (purple) and the template strand (cyan) in the insertion ternary complex. The intermolecular contacts involving the little finger are translocated by one nucleotide step on proceeding from the preinsertion binary complex (in A) to the insertion ternary complex (in C) upon dCTP binding.
(D) Intermolecular contacts between the little-finger domain (purple) and the primer strand (green) in the insertion ternary complex. The intermolecular contacts involving the little finger are translocated by one nucleotide step on proceeding from the preinsertion binary complex (in B) to the insertion ternary complex (in D) upon dCTP binding.
(E) Intermolecular contacts between the little-finger domain (purple) and the template strand (cyan) in the postinsertion binary complex. The intermolecular contacts involving the little finger are retained on proceeding from the insertion ternary complex (in C) to postinsertion binary complex (in E) on dCTP incorporation.
(F) Intermolecular contacts between the little-finger domain (purple) and the primer strand (green) in the postinsertion binary complex. The intermolecular contacts involving the little finger are retained on proceeding from the insertion ternary complex (in D) to postinsertion binary complex (in F) on dCTP incorporation.