Figure 1

Surface model of the three-dimensional structure of the rear-face of the mutated PGA. The existing Lys in the wt protein are yellow; the residues introduced by PCR mutagenesis that resulted in an active enzyme are in green; residues that had a negative effect are in blue and red, which indicate toxicity or maturation defect, respectively (top of the figure). The desired effect is to create the link with the resin on the rear-face of the protein in order to obtain a derivative with a freely accessible active site for the substrate (bottom of the figure).