Figure 1

Structure-based design of alanine scanning mutagenesis. (a) Schematic presentation of Plg structure, indicating the 5 kringle domains and the catalytic domain (μPlg)²³. (b) Synthetic gene and protein sequence of μPlg, with sequences of the loops labeled. (c) Loops 1–6 structure and residues around the active site catalytic triad of µPlm. The published µPlm structure⁵³ were used. Numbering system is derived from the full length Plg²³, and the amino acid number of the first amino acid in each loop is labeled. A total of 36 amino acids are labeled as the loop structure here. d Contact region between µPlm and the γ-domain of SK (labeled as ϓ-SK). A total of 18 amino acids are labeled as the loop structure here. Loop 7 is the 70–80 loop and loop 8 is the autolysis loop. In the structural presentation: the backbone, Wire; loops, Tubes with protein sidechains Wire; active side triad, Ball and Stick.