FIG 3.

GspD forms heat-resistant multimers that mislocalize to the inner membrane, where the other V. cholerae secretins do not. (A) Cultures were grown to mid-log phase when protein production was induced by the addition of arabinose for 1 h. Samples were resuspended in sample buffer containing SDS and boiled for 5 min before separation by electrophoresis. (B) Induced cultures were fractionated into total membrane (M), inner membrane (IM), and outer membrane (OM) fractions, and GspD multimer and monomers were detected using anti-His antibody. OmpT-FLAG and ToxR were used as outer membrane and inner membrane controls, respectively. Figure is representative of 3 experiments.