FIG. 2.

(a) The amino acid substitutions seen in the PBP1 transpeptidase domain from B258 were divided into clusters based on their sequence proximity to each other. Strains 26695, B258, and 26695_T contained all clusters. Other transformants contained different combinations of clusters as indicated by the numbers in their names. (b) Alpha-carbon trace representation of transpeptidase region of PBP1 of 26695 with the side chains of amino acids changed to stick representation (all other amino acids are deleted for clarity). The color code is by amino acid type (green, hydrophobic; yellow, polar; blue, polar positively charged; red, polar negatively charged). (c) Alpha-carbon trace model of transpeptidase region of PBP1 of B258 showing amino acid substitutions as described for panel b.