FIG 1.

Specific charges in the cavity region of MurJ are required for function. (A) Structural model of MurJ (14) showing charged residues in the cavity region that are critical for function. Shown are the front view from the membrane plane with approximate membrane boundaries marked (left) and the top view from the periplasm (right). Relevant positively (blue) and negatively (red) charged side chains are rendered as spheres. (B) Summary of the effect on MurJ function conferred by Ala and Cys substitutions (14) and substitutions to the opposite (R/K to E or D/E to R/K) or conserved (R to K or D/E to E/D) charge at each residue (left column) shown in panel A. Phenotypes are given as total loss of function (TLOF) if the allele does not complement a ΔmurJ chromosomal deletion, partial loss of function (PLOF) if the allele complements a ΔmurJ chromosomal deletion but confers sensitivity to low-osmolarity conditions, and functional (F) if the allele does not confer any mutant phenotype. Phenotypes were assessed as described in Materials and Methods. Data for Cys substitutions are described by Butler et al. (14); data for changes to Ala and the opposite and conserved charge are described in Results and Tables S1 and S2 in the supplemental material. ND, not done.