FIG 1 .
The N terminus of EIIAGlc forms an AH that mediates membrane association and is essential for PTS-dependent activation of sugar transport through EIICs. (A and B) Immunoblots of the lysate, cytoplasmic, and membrane fractions of control or ΔEIIBCGlc ΔmshH Δcya mutant (ΔΔΔ) V. cholerae cells expressing affinity-tagged full-length EIIAGlc (FL) or Δ16 EIIAGlc (Δ16). The membrane association index (MAI) with respect to FL is given below. (C) Immunoblots of the lysate, cytoplasmic, and membrane fractions of wild-type V. cholerae expressing neon green alone (AH−) or as a C-terminal fusion to the AH of EIIAGlc (AH+) encoded on a plasmid. The membrane association index (MAI) with respect to AH− is given below. (D to F) A615 measured over time for V. cholerae expressing the indicated EIIAGlc alleles or deletion (ΔEIIA) and cultured in minimal medium supplemented with pH indicators and sucrose (D), trehalose (E), and N-acetylmuramic acid (F). The decrease in A615 indicates medium acidification due to transport and fermentation of the indicated sugar. Results are representative of three independent experiments.