Figure 2. Enrichment of second-site suppressor population for L83S CcdB inactive mutant following multiple rounds of Fluorescence Activated Cell Sorting (FACS).
62 pM of Gyrase-3xFLAG was used in all cases for analysis. 4 nM, 1 nM and 0.25 nM Gyrase-3xFLAG was used for the three rounds of sort respectively. The population gated in green shows the parent inactive mutant L83S, while that in magenta shows the sorted population which has higher surface expression and tighter binding to the ligand than L83S. Sort details for different libraries of CcdB are summarized in Supplementary file 1.