FIG. 5.

The class C sortases encoded in the islet are required for pilus polymerization. The bacterial and culture fractions (cell wall [cw], protoplast [pplast], and culture supernatant [sup]) of an srtC1-C3 triple sortase deletion mutant strain were separated by SDS-polyacrylamide gel electrophoresis, transferred to nitrocellulose, and probed with antiserum against RrgB. The bacterial cell wall fraction of the wild type was run as a positive control. The values on the left are molecular weight marker sizes in kilodaltons.