From Structure-Function Analyses to Protein Engineering for Practical Applications of DNA Ligase

Figure 14

Nick-joining activities of the wild type and mutant proteins. (a) Initial reaction rates for the wild type (WT), K558A (1ala), K554A/K558A (2ala), Q547A/K554A/K558A (3ala), C-terminal 4 residue-deleted mutant d4 (open circles), d8 (open squares), and d15 (open triangles) enzymes, represented by time course data. (b) Initial reaction rates for WT, 3ala, D540A/3ala, D540A, D540S, D540R, and D540K. (c) Nick-joining activities of Asp540 mutants at each temperature for 15 min. The extents of nick ligation by D540A (open circles), D540S (open squares), D540R (open triangles), and D540K (open diamonds) were plotted as a function of time. (d) Nick-joining activities of Asp540 mutants at each temperature for 120 min. Error bars represent the standard deviation () [103].

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