FIG. 4.

SrtA is not required for pilus polymerization or localization to the cell wall. (A) Bacterial and culture fractions (cell wall [cw], protoplast [pplast], and culture supernatant [sup]) of the wild type (wt) and an srtA strain were separated by SDS-polyacrylamide gel electrophoresis, transferred to nitrocellulose, and probed with antiserum against RrgB. As a negative control, an rrgB strain was included. The values on the left are molecular weight marker sizes in kilodaltons. (B) Quantification of RrgB in HMW pili with a ¹²⁵I-labeled secondary antibody. (C) The amount of HMW RrgB protein in each sample is shown. These values are the averages of two separate experiments, one of which is the blot shown in panel B.