Fig. S3.

T18-PilA mutant fusions are stable. (A) α-PAK PilA (1:7,500 dilution) Western blot was performed to determine the stability of all T18-PilA point mutants generated in E. coli DH5α. Although there is some difference in protein levels, each of the point mutants are present and lower abundance mutants do not necessarily affect β-galactosidase output, as mutations such as PilA M16A or Q23A are at low levels but interact robustly with PilS in the BACTH assay. (B) Despite being present at a lower abundance than most other T18-PilA variants, PilA E5K is still present in high enough abundance to reveal interactions in the BACTH assay where they are present.