Fig 5.

The disulfide bond is important for stability of a ^TTGFP-FtsN^SPOR fusion protein. (A) Reduced septal localization of ^TTGFP-FtsN^SPOR in the absence of DsbA. The indicated strains carrying pDSW992 were grown to mid-log phase, immobilized on an agarose pad, and photographed under phase-contrast (top) and fluorescence (bottom) conditions. (B) Reduced abundance of ^TTGFP-FtsN^SPOR in the absence of DsbA. The indicated strains carrying pDSW992 or pDSW997 were grown to mid-log phase, and levels of ^TTGFP-FtsN^SPOR or ^TTGFP-DamX^SPOR were determined by Western blotting with anti-GFP antibody. (C) Effects of Cys-to-Ala substitutions on the stability of ^TTGFP-FtsN^SPOR. Wild-type strain EC251 carrying plasmids that direct expression of wild-type ^TTGFP-FtsN^SPOR or the indicated mutant derivatives was analyzed as described for panel B.