The genes pykA and xylR are posttranscriptionally regulated by DicF. The genes pykA and xylR are posttranscriptionally regulated by DicF. (A) A schematic of reporter fusion constructs used in this experiment. Selected candidates from Table 1 were fused to ′lacZ and integrated as single copies on the E. coli chromosome, under the control of either an arabinose-inducible (PBAD) promoter or a constitutive (Cp19) promoter (see text), followed by the 5′ untranslated region (5′ UTR) of the gene and 10 to 20 amino acids of the coding sequence. (B) The fusions created in a wt E. coli host strain were assayed for β-galactosidase activity after DicF expression from a plasmid. The specific activities (quantified in Miller units) were normalized to the vector control of the corresponding strain to yield relative-activity data. The targets chosen for further study (indicated in bold) were up- or downregulated by DicF at least 2-fold. Divya Balasubramanian et al. mSystems 2016; doi:10.1128/mSystems.00021-15