Fig. 5. Amino acid substitutions in motif II of selected active hPolη mutants and unselected mutants. Mutations observed in selected clones harboring one (A), two (B) or three (C) amino acid changes and mutations (D) in unselected clones. Asterisks indicate nonsense codons. Substitutions at each residue are listed, along with the number of times each substitution was observed. The double mutants are: E53N,A68P; E53Q,K69M; R55L,A56G; R55L,F57L; A56S,S62V; A56V,S62G; F57S,S62G; F57T,D66A; G58R,K70M; V59I,K69R; V59I,K70M; T60S,R61T; T60S,S62T; T60S,D66V; T60S,D66V; R61T,L71F; R61K,C72Y; S62R,W64R; S62R,D66N; S62R,K70N; S62C,P73Q; S62N,P73S; M63G,W64R; M63T,D66E; M63I,K69M; W64R,D67H; W64C,K70R; A65G,A68G; D67A,K70M. The triple mutants are: E53A,T60S,A65T; E53L,R61L,D66T; E53L,W64C,D66N; E53D,W64C,L71F; A56S,F57L,D67R; A56E,D67N,L71I; T60A,A65F,K70N; T60N,A65G,K70M; T60A,D67E,K70N; R61K,D66V,D67H; S62R,W64C,P73A; M63I,W64C,D66E; W64R,D67V,P73Q; W64R,A68G,K70Q; A65G,D66V,K69R; A65R,K69T,L71S; D66T,K69R,K70Q.