Journal: Journal of Bacteriology
Article Title: Escherichia coli is poised to grow using 5′-deoxynucleosides via MtnR and CRP regulation of DHAP shunt gene expression
doi: 10.1128/jb.00280-25
Figure Lengend Snippet: DHAP shunt 5′-UTR regions required for operon expression and repression by MtnR. ( A ) E. coli ATCC 25922 DHAP shunt genomic context and sections of 5′-UTR used for construction of plasmids (pLacZ###) with promoter– lacZ fusions. ( B, D ) LacZ activity assays from cell extracts of wild-type E. coli ATCC 25922 and ( C, E ) LacZ activity assays from cell extracts of MtnR deletion strain (Δ mtnR ) containing the indicated DHAP shunt 5′-UTR– lacZ fusion plasmids when grown with either 5 mM glucose (Glc), 5 mM glucose plus 5 mM 5dR (Glc + 5dR), or 5dR as the carbon source. The pLacZ control is a Lac promoter– lacZ fusion without added IPTG. Average and standard deviation error bars are for n = 3 independent replicates. ** P > 0.05, * P > 0.1; two-tailed t -test. ( F ) Log 2 -fold change in mtnK mRNA expression from transcriptomic analysis ( ; ) and measured by qRT-PCR for wild-type ATCC 25922 (WT), mtnR deletion strain (Δ mtnR ), and mtnR deletion strain complemented with mtnR from a plasmid (Δ mtnR + pmtnR). Tetracycline (10 ng/mL) was added to induce expression of mtnR from pmtnR plasmid. qRT-PCR average and standard deviation error bars are for n = 4 independent biological replicates except for WT Glc + 5dR versus Glc ( n = 8) and Δ mtnR + pmtnR Glc + 5dR versus Glc ( n = 3). ** P > 0.05; two-tailed t -test.
Article Snippet: Regions upstream of the DHAP shunt operon were amplified from E. coli ATCC 25922 genomic DNA as templates for sequencing ladders.
Techniques: Expressing, Activity Assay, Control, Standard Deviation, Two Tailed Test, Quantitative RT-PCR, Plasmid Preparation