Figure 2.

Dynamics of flagellar class 2 and class 3 gene expression in (A) wild type, (B) ΔflgM, (C) ΔfliZ, (D) ΔfliT, and (E) ΔfliD. Class 2 and class 3 genes have been represented by solid and dashed lines, respectively. Here, class 2 genes represent the genes encoding the constituent proteins of HBB. Class 3 genes include the genes encoding filament, motor and chemotaxis proteins. A. U. denotes arbitrary units. For mutants, the expression levels of class 2 and class 3 genes have been normalized with respect to those in wild type and subsequently plotted. The plot for wild type shows the characteristic delay in class 3 gene expression. FlgM is responsible for this delay as class 2 and class 3 genes are expressed at similar time in ΔflgM as shown in B. Deletion of the activators FliZ and FliD results in reduced expression levels of class 2 and class 3 genes, while, deletion of the repressor FliT leads to increase in the expression levels. Standard deviation in each curve is <10% of the mean values.