FIG 7 .

Regulation of BvgS in the absence of the PAS domain. (A) Sequence of the linker of BvgS_ΔPAS-R1 and substitutions introduced to affect coiled-coil stability. The variants are denoted R1-1L, R1-2L and R1-3L to indicate the presence of 1, 2, or 3 Ala-to-Leu substitutions, respectively. (B) The ptx-lacZ reporter was used to determine the activities of BvgS_ΔPAS-R1 and its variants. The fhaB-lacZ reporter also did not result in any activity being detected for the variants with 2 or 3 additional Leu residues (see Fig. S3B in the supplemental material). (C) Effect of introducing an S-S bond between the lobes of the VFT1 domain on the activities of wt BvgS (WT) and the indicated variants using the ptx-lacZ reporter, compared with the activities of the corresponding variants without the S-S bond. Where indicated, the reducing agent TCEP [tris(2-carboxyethyl)phosphine] was added to the cultures at 10 mM for the last 6 h to reduce the S-S bond in VFT1. The means and standard errors of the means are given.