Fig. 2: CryoEM captures multiple steps along the DNA proofreading pathway.

a Polγ structures representing the major steps of the proofreading process. The complexes (Structures I–IV, VII, VIII, and IX, surface representation) are shown in the same orientation of their catalytic subunits. The Mismatch Removal complex is modeled using Structure IX to illustrate the final step of the proofreading. b The trajectory of the mismatched base during proofreading. The structures were aligned using the Polγ_A subunits. The mismatched base of the primer is shown. c The change of DNA trajectory during proofreading. Structures are shown in the same orientation of their catalytic subunit. Change in DNA trajectory (degrees) is indicated relative to the DNA axis in the Mismatch-Sensing complex.