Fig. 2: Active sites of the Polζ complexes with mismatched and matched DNA.
From: Cryo-EM structure of translesion DNA synthesis polymerase ζ with a base pair mismatch
a Close-up view of the Polζ active site in the mismatched DNA complex depicting the key residues from the fingers (yellow) and palm (blue) domains in close proximity to the replicative end of the template-primer DNA (red) and incoming dCTP (red). A green sphere depicts metal ion B. b Close-up view of the Polζ active site in the matched DNA complex (PDB ID: 6V93). The coloring scheme is the same as in a., except that the template-primer and dCTP are shown in gray. The complete side chains for few residues including Lys1061, Lys1086, and Arg1057 have not been built in mismatched DNA complex due to less well-defined cryo-EM density. c Overlay of equivalent template-primer segments and incoming dCTP for the mismatched (red) and matched (gray) DNA complexes. d Base pairing at the primer terminus in the matched (G:C, gray color) and mismatched (A:C, red color) complexes. e Position of putative 3’-OH (marked by a star) at the primer terminus relative to the incoming dCTP in the mismatched (red) and matched (gray) complexes.
