FIG. 7.
The purity and the activity of the Apn2 Ala59 mutant protein. (A) Two micrograms of the wild-type (wt) and the Ala59 mutant (A59) GST-Apn2 proteins was loaded on an 8% denaturing polyacrylamide gel and stained with Coomassie blue. Molecular mass standards with the indicated molecular masses are on the left. (B) The exonuclease activities of the wild-type and mutant GST-Apn2 proteins were compared by using two different DNA substrates. Lanes − contain reaction mixtures without any protein added.