Figure 2.

Ribbon representation of the transpeptidase domain of two types of N. gonorrhoeae PBP2 from resistant strains. The active site residues are shown as sticks, the substituted or inserted positions are shown by colored spheres. (a) Sequence XII, the D346a insertion is shown in blue; the F504L, A510V, A516G and P551S substitutions are in dull pink or magenta, to emphasize the importance of the latter substitutions in the resistance; (b) Distribution of the substitutions found in sequence XXXIX shown as colored spheres. Positions demonstrated as important for resistance in different studies are shown in violet [22], magenta [34] and yellow [36]. Yellow substitutions are specific of resistance to third generation cephalosporins.