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- Gonzalez, Grecia M., et al.
(författare)
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Structure of the Escherichia coli ProQ RNA-binding protein
- 2017
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Ingår i: RNA. - : COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT. - 1355-8382 .- 1469-9001. ; 23:5, s. 696-711
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Tidskriftsartikel (refereegranskat)abstract
- The protein ProQ has recently been identified as a global small noncoding RNA-binding protein in Salmonella, and a similar role is anticipated for its numerous homologs in divergent bacterial species. We report the solution structure of Escherichia call ProQ, revealing an N-terminal FinO-like domain, a C-terminal domain that unexpectedly has a Tudor domain fold commonly found in eukaryotes, and an elongated bridging intradomain linker that is flexible but nonetheless incompressible. Structure-based sequence analysis suggests that the Tudor domain was acquired through horizontal gene transfer and gene fusion to the ancestral FinO-like domain. Through a combination of biochemical and biophysical approaches, we have mapped putative RNA-binding surfaces on all three domains of ProQ and modeled the protein's conformation in the apo and RNA-bound forms. Taken together, these data suggest how the FinO, Tudor, and linker domains of ProQ cooperate to recognize complex RNA structures and serve to promote RNA-mediated regulation.
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| 3. |
- Krypotou, Emilia, et al.
(författare)
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Control of Bacterial Virulence through the Peptide Signature of the Habitat
- 2019
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Ingår i: Cell Reports. - : Elsevier. - 2211-1247. ; 26:7, s. 1815-1827
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Tidskriftsartikel (refereegranskat)abstract
- To optimize fitness, pathogens selectively activate their virulence program upon host entry. Here, we report that the facultative intracellular bacterium Listeria monocytogenes exploits exogenous oligopeptides, a ubiquitous organic N source, to sense the environment and control the activity of its virulence transcriptional activator, PrfA. Using a genetic screen in adsorbent- treated ( PrfA-inducing) medium, we found that PrfA is functionally regulated by the balance between activating and inhibitory nutritional peptides scavenged via the Opp transport system. Activating peptides provide essential cysteine precursor for the PrfA-inducing cofactor glutathione ( GSH). Non-cysteine-containing peptides cause promiscuous PrfA inhibition. Biophysical and co-crystallization studies reveal that peptides inhibit PrfA through steric blockade of the GSH binding site, a regulation mechanism directly linking bacterial virulence and metabolism. L. monocytogenes mutant analysis in macrophages and our functional data support a model in which changes in the balance of antagonistic Oppimported oligopeptides promote PrfA induction intra-cellularly and PrfA repression outside the host.
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