FIG 1.
Physiological effects of deletion and overexpression of the mraZ gene. (A) The dcw cluster of E. coli, showing the location of the Pmra promoter upstream of mraZ and highlighting the position of mraZ and mraW at the beginning of the cluster. (B) Spot dilution assay of WT and mraZ and mraW overexpressing MG1655 cells on LB plates containing 0.1 μg/ml trimethoprim. Shown from left to right are undiluted and 10−1 to 10−5 diluted samples of a mid-logarithmic-phase culture grown in LB with no antibiotic. (C) Spot dilution assay of WT and mraZ and mraW mutant MG1655 on LB plates containing 1 mM IPTG to fully induce gene expression. Shown from left to right are undiluted and 10−1 to 10−5 diluted samples of a mid-logarithmic-phase culture grown in LB with no induction. (D) Growth curves of the same strains as in panel B either uninduced or induced with 1 mM IPTG. V, vector.