| Autor: |
Lalaouna, David, Eyraud, Alex, Devinck, Aurélie, Prévost, Karine, Massé, Eric |
| Předmět: |
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| Zdroj: |
Molecular Microbiology; Feb2019, Vol. 111 Issue 2, p473-486, 14p, 4 Diagrams, 1 Chart, 3 Graphs |
| Abstrakt: |
Summary: GcvB small RNA is described as post‐transcriptional regulator of 1–2% of all mRNAs in Escherichia coli and Salmonella Typhimurium. At least 24 GcvB:mRNA interactions have been validated in vivo, establishing the largest characterized sRNA targetome. By performing MS2‐affinity purification coupled with RNA sequencing (MAPS) technology, we identified seven additional mRNAs negatively regulated by GcvB in E. coli. Contrary to the vast majority of previously known targets, which pair to the well‐conserved GcvB R1 region, we validated four mRNAs targeted by GcvB R3 region. This indicates that base‐pairing through R3 seed sequence seems relatively common. We also noticed unusual GcvB pairing sites in the coding sequence of two target mRNAs. One of these target mRNAs has a pairing site displaying a unique ACA motif, suggesting that GcvB could hijack a translational enhancer element. The second target mRNA is likely regulated via an active RNase E‐mediated mRNA degradation mechanism. Remarkably, we confirmed the importance of the sRNA sponge SroC in the fine‐tuning control of GcvB activity in function of growth conditions such as growth phase and nutrient availability. GcvB sRNA negatively regulates at least 31 target mRNAs mostly involved in amino acid metabolism in Escherichia coli and Salmonella Typhimurium. Two main regions of GcvB, referred to as R1 and R3, are required to base‐pair with described target mRNAs. Remarkably, SroC, a GcvB sRNA sponge, is of prime importance to release GcvB‐dependent repression in stationary phase of growth and in minimal medium. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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