Figure 2.
Analysis of affinity-purified recombinant WRN proteins. (A) Diagram of the constructs used to produce the recombinant WRN proteins. hWRN, full length wild-type human protein; hWRN-N333, human N-terminal WRN fragment containing amino acids 1–333; hWRN-N333E84A, human N-terminal WRN fragment exonuclease mutant harboring a point mutation from Glu (E) to Ala (A) at amino acid 84; mWRN-N328, mouse N-terminal WRN fragment containing amino acids 1–328. The exonuclease domain is designated by a hatched box and the helicase domain by a box with horizontal bars. NLS, nuclear localization signal. (B and C) Full-length human wild-type WRN. Wild-type hWRN (1 µg) was analyzed by 10% SDS–PAGE stained with Coomassie brilliant blue (B) and western blotting using a polyclonal antibody against the hWRN C-terminal region (C). (D and E) N-terminal WRN fragments. hWRN-N333, hWRN-N333E84A and mWRN-N328 proteins (2 µg each) were analyzed by 12% SDS–PAGE stained with Coomassie brilliant blue (D) and western blotting using a polyclonal antibody against the hWRN N-terminal region (E).