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. 2012 Jun 13;4(6):417–429. doi: 10.18632/aging.100463

Figure 5. Mutations in RQC domain of WRN result in significant decrease of exonuclease activity and strand annealing activity.

Figure 5

(A) Exonuclease activity of WRN mutants was severely reduced. 5, 10, 20 nM WRN wild type (lane 2 to 4) or WRN variants (lane 5 to 7, R993A; lane 8 to 10, F1037A; lane 11 to 13, R993A/F1037A) were incubated with 0.5 nM 5' overhang duplex substrate. Products were separated on 14 % denaturing polyacrylamide gel. (B) Ku70/80 heterodimeric protein is not able to stimulate exonuclease activity of WRN mutants. 10 nM WRN wild type (lane 4 to 6) or WRN mutants (lane 7 to 9, R993A; lane 10 to 12, F1037A; lane 13 to 15, R993A/F1037A) were incubated with 5, 10, 20 nM Ku heterodimer and substrate. (C) WRN variants exhibit significantly lower strand annealing activity than the WRN wild type protein. 1, 2, 5 nM WRN wild type or WRN RQC variants were incubated with 0.5 nM DNA substrate at 37 °C for 15 min.