The Impact of the Major Endoribonucleases RNase E and RNase III and of the sRNA StsR on Photosynthesis Gene Expression in Is Growth-Phase-Dependent.

is a facultative phototrophic bacterium that performs aerobic respiration when oxygen is available. Only when oxygen is present at low concentrations or absent are pigment-protein complexes formed, and anoxygenic photosynthesis generates ATP. The regulation of photosynthesis genes in response to oxygen and light has been investigated for decades, with a focus on the regulation of transcription.

Identifying components of the phage LambdaSo lysis system.

Unlabelled: Phage-induced lysis of Gram-negative bacterial hosts usually requires a set of phage lysis proteins, a holin, an endopeptidase, and a spanin system, to disrupt each of the three cell envelope layers. Genome annotations and previous studies identified a gene region in the prophage LambdaSo, which comprises potential holin- and endolysin-encoding genes but lacks an obvious spanin system. By a combination of candidate approaches, mutant screening, characterization, and microscopy, we found that LambdaSo uses a pinholin/signal-anchor-release (SAR) endolysin system to induce proton leakage and degradation of the cell wall.

Function of the RNA-targeting class 2 type VI CRISPR Cas system of .

Bacteria use CRISPR Cas systems to defend against invading foreign nucleic acids, e.g., phage genomes, plasmids or mobile genetic elements.

Genetic Engineering of Increases Curdlan Production through Increased Expression of the Genes.

Curdlan is a water-insoluble polymer that has structure and gelling properties that are useful in a wide variety of applications such as in medicine, cosmetics, packaging and the food and building industries. The capacity to produce curdlan has been detected in certain soil-dwelling bacteria of various phyla, although the role of curdlan in their survival remains unclear. One of the major limitations of the extensive use of curdlan in industry is the high cost of production during fermentation, partly because production involves specific nutritional requirements such as nitrogen limitation.

Analysis of sRNAs and Their mRNA Targets in Sinorhizobium meliloti: Focus on Half-Life Determination.

Regulation of gene expression at the level of RNA and/or by regulatory RNA is an integral part of the regulatory circuits in all living cells. In bacteria, transcription and translation can be coupled, enabling regulation by transcriptional attenuation, a mechanism based on mutually exclusive structures in nascent mRNA. Transcriptional attenuation gives rise to small RNAs that are well suited to act in trans by either base pairing or ligand binding.

Daptomycin-Impregnated PMMA Cement against Vancomycin-Resistant Germs: Dosage, Handling, Elution, Mechanical Stability, and Effectiveness.

Background: The number of periprosthetic joint infections caused by vancomycin-resistant pathogens is increasing. Currently, no PMMA cement is commercially available to cover VRE. Daptomycin shows promising results in treating infection, offering a good safety profile and a reduced risk of developing resistance.

Silicon nanoparticles: A promising approach for control of biofilms.

Objectives: The current study aimed to investigate the control and treatment of biofilm-producing isolates of using silicon nanoparticles (SiNPs).

Materials And Methods: Biofilm-producing isolates of were recovered from various food samples and identified through fluorescent green colony formation on selective and differential media, as well as the amplification of and genes. Tube methods, Congo-red agar method, and scanning electron microscopy (SEM) were used to study biofilm phenotypes.

The Functionality of IbpA from Is Governed by Dynamic Rearrangement of Its Globular-Fibrillar Quaternary Structure.

Small heat shock proteins (sHSPs) represent a first line of stress defense in many bacteria. The primary function of these molecular chaperones involves preventing irreversible protein denaturation and aggregation. In , fibrillar IbpA binds unfolded proteins and keeps them in a folding-competent state.

RNase III participates in control of quorum sensing, pigmentation and oxidative stress resistance in Rhodobacter sphaeroides.

RNase III is a dsRNA-specific endoribonuclease, highly conserved in bacteria and eukarya. In this study, we analysed the effects of inactivation of RNase III on the transcriptome and the phenotype of the facultative phototrophic α-proteobacterium Rhodobacter sphaeroides. RNA-seq revealed an unexpectedly high amount of genes with increased expression located directly downstream to the rRNA operons.

Design-Build-Test of Synthetic Promoters for Inducible Gene Regulation in Alphaproteobacteria.

Inducible gene expression is useful for biotechnological applications and for studying gene regulation and function in bacteria. Many inducible systems that perform in model organisms such as the Gammaproteobacterium do not perform well in other bacteria that are of biotechnological interest. Typical problems include weak or leaky expression.

The Small RNA-Binding Protein CcaF1 Promotes Formation of Photosynthetic Complexes in .

In natural habitats, bacteria frequently need to adapt to changing environmental conditions. Regulation of transcription plays an important role in this process. However, riboregulation also contributes substantially to adaptation.

Polarity of c-di-GMP synthesis and degradation.

The bacterial cell pole has long been recognized as a defined compartment for enzymatic activities that are important or even vital for the cell. Polarity of diguanylate cyclases and phosphodiesterases, enzymes that synthesize and degrade the second messenger c-di-GMP, has now been demonstrated for several bacterial systems. Here we review these polar regulatory systems and show how the asymmetry of c-di-GMP production and turnover in concert with different modes of activation and deactivation creates heterogeneity in cellular c-di-GMP levels.

Unraveling the small proteome of the plant symbiont by ribosome profiling and proteogenomics.

The soil-dwelling plant symbiont is a major model organism of Alphaproteobacteria. Despite numerous detailed OMICS studies, information about small open reading frame (sORF)-encoded proteins (SEPs) is largely missing, because sORFs are poorly annotated and SEPs are hard to detect experimentally. However, given that SEPs can fulfill important functions, identification of translated sORFs is critical for analyzing their roles in bacterial physiology.

Bacterial multicellular behavior in antiviral defense.

Multicellular behavior benefits seemingly simple organisms such as bacteria, by improving nutrient uptake, resistance to stresses, or by providing advantages in predatory interactions. Several recent studies have shown that this also extends to the defense against bacteriophages, which are omnipresent in almost all habitats. In this review, we summarize strategies conferring protection against phage infection at the multicellular level, covering secretion of small antiphage molecules or membrane vesicles, the role of quorum sensing in phage defense, the development of transient phage resistance, and the impact of biofilm components and architecture.

Ribonuclease E strongly impacts bacterial adaptation to different growth conditions.

Adaptation of bacteria to changes in their environment is often accomplished by changes of the transcriptome. While we learned a lot on the impact of transcriptional regulation in bacterial adaptation over the last decades, much less is known on the role of ribonucleases. This study demonstrates an important function of the endoribonuclease RNase E in the adaptation to different growth conditions.

A Small RNA, UdsC, Interacts with the R mRNA and Affects the Motility and Stress Resistance of .

sRNAs have an important role in the regulation of bacterial gene expression. The sRNA, UdsC, of is derived from the 3' UTR of the RSP_7527 mRNA, which encodes a hypothetical protein. Here, we showed the effect of UdsC on the resistance of to hydrogen peroxide and on its motility.

FlrA-independent production of flagellar proteins is required for proper flagellation in Shewanella putrefaciens.

Flagella are multiprotein complexes whose assembly and positioning require complex spatiotemporal control. Flagellar assembly is thought to be controlled by several transcriptional tiers, which are mediated through various master regulators. Here, we revisited the regulation of flagellar genes in polarly flagellated gammaproteobacteria by the regulators FlrA, RpoN (σ ) and FliA (σ ) in Shewanella putrefaciens CN-32 at the transcript and protein level.

Incoherent dual regulation by a SAM-II riboswitch controlling translation at a distance.

In , the methionine biosynthesis genes and are preceded by S-adenosyl-L-methionine (SAM) riboswitches of the SAM-II class. Upon SAM binding, structural changes in the riboswitch were predicted to cause transcriptional termination, generating the sRNA RZ. By contrast, the riboswitch was predicted to regulate translation from an AUG1 codon.

Wrapped Up: The Motility of Polarly Flagellated Bacteria.

A huge number of bacterial species are motile by flagella, which allow them to actively move toward favorable environments and away from hazardous areas and to conquer new habitats. The general perception of flagellum-mediated movement and chemotaxis is dominated by the paradigm, with its peritrichous flagellation and its famous run-and-tumble navigation pattern, which has shaped the view on how bacteria swim and navigate in chemical gradients. However, a significant amount-more likely the majority-of bacterial species exhibit a (bi)polar flagellar localization pattern instead of lateral flagella.

A hydrophilic microenvironment in the substrate-translocating groove of the YidC membrane insertase is essential for enzyme function.

The YidC family of proteins are membrane insertases that catalyze the translocation of the periplasmic domain of membrane proteins via a hydrophilic groove located within the inner leaflet of the membrane. All homologs have a strictly conserved, positively charged residue in the center of this groove. In Bacillus subtilis, the positively charged residue has been proposed to be essential for interacting with negatively charged residues of the substrate, supporting a hypothesis that YidC catalyzes insertion via an early-step electrostatic attraction mechanism.

Maturation of UTR-Derived sRNAs Is Modulated during Adaptation to Different Growth Conditions.

Small regulatory RNAs play a major role in bacterial gene regulation by binding their target mRNAs, which mostly influences the stability or translation of the target. Expression levels of sRNAs are often regulated by their own promoters, but recent reports have highlighted the presence and importance of sRNAs that are derived from mRNA 3' untranslated regions (UTRs). In this study, we investigated the maturation of 5' and 3' UTR-derived sRNAs on a global scale in the facultative phototrophic alphaproteobacterium .

Riboregulation in bacteria: From general principles to novel mechanisms of the trp attenuator and its sRNA and peptide products.

Gene expression strategies ensuring bacterial survival and competitiveness rely on cis- and trans-acting RNA-regulators (riboregulators). Among the cis-acting riboregulators are transcriptional and translational attenuators, and antisense RNAs (asRNAs). The trans-acting riboregulators are small RNAs (sRNAs) that bind proteins or base pairs with other RNAs.

A Complex Network of Sigma Factors and sRNA StsR Regulates Stress Responses in .

Adaptation of bacteria to a changing environment is often accompanied by remodeling of the transcriptome. In the facultative phototroph the alternative sigma factors RpoE, RpoHI and RpoHII play an important role in a variety of stress responses, including heat, oxidative stress and nutrient limitation. Photooxidative stress caused by the simultaneous presence of chlorophylls, light and oxygen is a special challenge for phototrophic organisms.

sRNA-mediated RNA processing regulates bacterial cell division.

Tight control of cell division is essential for survival of most organisms. For prokaryotes, the regulatory mechanisms involved in the control of cell division are mostly unknown. We show that the small non-coding sRNA StsR has an important role in controlling cell division and growth in the alpha-proteobacterium Rhodobacter sphaeroides.