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. 2017 Sep 12;7:11326. doi: 10.1038/s41598-017-10902-0

Figure 6.

Figure 6

PNPase is a repressor of yeeJ transcription. (A) Activity of the yeeJ promoter-lacZ fusion assessed by β-galactosidase quantitation in wild type MG1655 (MG1655 ΔlacIZ ΔyeeJ::lacZ), an isogenic pnp mutant, complemented pnp mutant with plasmid pPNP2 and pnp mutant carrying the empty plasmid pZE12CFP. β-galactosidase levels were measured in each individual strain with different IPTG concentrations (0, 0.1 and 1 mM) from an overnight culture. Mutation of pnp gene increased PyeeJ activity and complementation of the pnp mutation restored the PyeeJ basal activity to wild type levels. All experiments were performed in triplicate. One-way ANOVA statistical analysis: ***P < 0.0001; **P < 0.001. (B) Transcription of the yeeJ gene in wild type MG1655, isogenic pnp mutant, complemented mutant with plasmid pPNP2 and the PcLyeeJ strain. The relative fold difference in yeeJ transcript levels relative to MG1655 as determined by qRT-PCR using the 2−ΔΔCT method. Mutation of the pnp gene led to an increase in yeeJ mRNA transcript levels, and complementation of the mutant with a plasmid containing pnp (pPNP) restored yeeJ mRNA transcripts to wild type level. All experiments were performed in triplicate. One-way ANOVA statistical analysis was performed using MG1655 Δpnp as reference: ***P < 0.0001.