12,920 results match your criteria Molecular Microbiology [Journal]


Specific amino acid substitutions in β strand S2 of FtsZ cause spiraling septation and impair assembly cooperativity in Streptomyces spp.

Mol Microbiol 2019 Apr 19. Epub 2019 Apr 19.

Department of Biology, Lund University, 223 62, Lund, Sweden.

Bacterial cell division is orchestrated by the Z ring, which is formed by single-stranded treadmilling protofilaments of FtsZ. In Streptomyces, during sporulation, multiple Z rings are assembled and lead to formation of septa that divide a filamentous hyphal cell into tens of prespore compartments. We describe here mutant alleles of ftsZ in Streptomyces coelicolor and Streptomyces venezuelae that perturb cell division in such a way that constriction is initiated along irregular spiral-shaped paths rather than as regular septa perpendicular to the cell length axis. Read More

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http://dx.doi.org/10.1111/mmi.14262DOI Listing

The transcription factors ActR and SoxR differentially affect the phenazine tolerance of Agrobacterium tumefaciens.

Mol Microbiol 2019 Apr 19. Epub 2019 Apr 19.

Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.

Bacteria in soils encounter redox-active compounds, such as phenazines, that can generate oxidative stress, but the mechanisms by which different species tolerate these compounds are not fully understood. Here, we identify two transcription factors, ActR and SoxR, that play contrasting yet complementary roles in the tolerance of the soil bacterium Agrobacterium tumefaciens to phenazines. We show that ActR promotes phenazine tolerance by proactively driving expression of a more energy-efficient terminal oxidase at the expense of a less-efficient alternative, which may affect the rate at which phenazines abstract electrons from the electron transport chain and thereby generate reactive oxygen species. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1111/mmi.14263
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http://dx.doi.org/10.1111/mmi.14263DOI Listing
April 2019
1 Read

The role of C-terminal extensions in controlling ECF σ factor activity in the widely conserved groups ECF41 and ECF42.

Mol Microbiol 2019 Apr 16. Epub 2019 Apr 16.

LOEWE-Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, 35032, Marburg, Germany.

The activity of extracytoplasmic function σ factors (ECFs) is typically regulated by anti-σ factors. In a number of highly abundant ECF groups, including ECF41 and ECF42, σ-factors contain fused C-terminal protein domains, which provide the necessary regulatory function instead. Here, we identified the contact interface between the C-terminal extension and the core σ-factor regions required for controlling ECF activity. Read More

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http://dx.doi.org/10.1111/mmi.14261DOI Listing

Substrate and metabolic romiscuities of D-altronate dehydratase family proteins involved in non-phosphorylative D-arabinose, sugar acid, L-galactose, and L-fucose pathways from bacteria.

Mol Microbiol 2019 Apr 15. Epub 2019 Apr 15.

Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, 790-8566, Japan.

The gene context in microorganism genomes is of considerable help for identifying potential substrates. The C785_RS13685 gene in Herbaspirillum huttiense IAM 15032 is a member of the D-altronate dehydratase protein family, and which functions as a D-arabinonate dehydratase in vitro, is clustered with genes related to putative pentose metabolism. In the present study, further biochemical characterization and gene expression analyses revealed that L-xylonate is a physiological substrate that is ultimately converted to α-ketoglutarate via so-called Route II of a non-phosphorylative pathway. Read More

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http://dx.doi.org/10.1111/mmi.14259DOI Listing

Inhibition of autotransporter biogenesis by small molecules.

Mol Microbiol 2019 Apr 14. Epub 2019 Apr 14.

Department of Molecular Microbiology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Vrije Universiteit, Amsterdam, the Netherlands.

Disarming pathogens by targeting virulence factors is a promising alternative to classic antibiotics. Many virulence factors in Gram-negative bacteria are secreted via the autotransporter (AT) pathway, also known as Type 5 secretion. These factors are secreted with the assistance of two membrane-based protein complexes: Sec and Bam. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1111/mmi.14255
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http://dx.doi.org/10.1111/mmi.14255DOI Listing
April 2019
1 Read

Functional and mechanistic characterization of an atypical flavin reductase encoded by the pden_5119 gene in Paracoccus denitrificans.

Mol Microbiol 2019 Apr 11. Epub 2019 Apr 11.

Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Kotlářská 2, 611 37, Brno, Czech Republic.

Pden_5119, annotated as an NADPH-dependent FMN reductase, shows homology to proteins assisting in utilization of alkanesulfonates in other bacteria. Here we report that inactivation of the pden_5119 gene increased susceptibility to oxidative stress, decreased growth rate and increased growth yield; growth on lower alkanesulfonates as sulfur sources was not specifically influenced. Pden_5119 transcript rose in response to oxidative stressors, respiratory chain inhibitors and terminal oxidase downregulation. Read More

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http://dx.doi.org/10.1111/mmi.14260DOI Listing

Two binding proteins of the ABC transporter that confers growth of Bifidobacterium animalis subsp. lactis ATCC27673 on β-mannan possess distinct manno-oligosaccharide binding profiles.

Mol Microbiol 2019 Apr 4. Epub 2019 Apr 4.

Technical University of Denmark, Dept. of Biotechnology and Biomedicine, Søltofts Plads build. 224, 2800, Kgs Lyngby, Denmark.

Human gut bifidobacteria rely on ATP-binding cassette (ABC) transporters for oligosaccharide uptake. Multiple oligosaccharide-specific solute binding protein (SBP) genes are occasionally associated with a single ABC transporter, but the significance of this multiplicity remains unclear. Here, we characterize BlMnBP1 and BlMnBP2, the two SBPs associated to the β-manno-oligosaccharide (MnOS) ABC transporter in Bifidobacterium animalis subsp. Read More

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http://dx.doi.org/10.1111/mmi.14257DOI Listing
April 2019
1 Read

Alternariol as virulence and colonization factor of Alternaria alternata during plant infection.

Mol Microbiol 2019 Apr 4. Epub 2019 Apr 4.

Karlsruhe Institute of Technology (KIT) - South Campus, Dept. of Microbiology, Fritz-Haber-Weg 4, D-76131, Karlsruhe, Germany.

The filamentous fungus Alternaria alternata is a potent producer of many toxic secondary metabolites, which contaminate food and feed. The most prominent one is the polyketide-derived alternariol (AOH) and its derivative alternariol monomethyl ether (AME). Here we identified the gene cluster for the biosynthesis of AOH and AME by CRISPR/Cas9-mediated gene inactivation of several biosynthesis genes in A. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1111/mmi.14258
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http://dx.doi.org/10.1111/mmi.14258DOI Listing
April 2019
2 Reads

Cell-cell communication, chemotaxis and recruitment in Vibrio parahaemolyticus.

Mol Microbiol 2019 Apr 2. Epub 2019 Apr 2.

The Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, 52242, USA.

Motile bacteria are proficient at finding optimal environments for colonization. Often, they use chemotaxis to sense nutrient availability and dangerous concentrations of toxic chemicals. For many bacteria, the repertoire of chemoreceptors is large, suggesting they possess a broad palate with respect to sensing. Read More

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http://dx.doi.org/10.1111/mmi.14256DOI Listing
April 2019
1 Read

Apical assemblies of intermediate filament-like protein FilP are highly dynamic and affect polar growth determinant DivIVA in Streptomyces venezuelae.

Mol Microbiol 2019 Mar 31. Epub 2019 Mar 31.

Department of Biology, Lund University, Sölvegatan 35, 22362, Lund, Sweden.

Streptomyces spp. grow as branching hyphae, building the cell wall in restricted zones at hyphal tips. The organization of this mode of polar growth involves three coiled-coil proteins: DivIVA and Scy, which form apical protein complexes referred to as polarisomes; and the intermediate filament-like protein FilP, which influences cell shape and interacts with both Scy and DivIVA. Read More

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http://dx.doi.org/10.1111/mmi.14253DOI Listing
March 2019
1 Read

Sodium-powered stators of the bacterial flagellar motor can generate torque in the presence of phenamil with mutations near the peptidoglycan-binding region.

Mol Microbiol 2019 Mar 30. Epub 2019 Mar 30.

School of Biotechnology and Biomolecular Science, University of New South Wales, Kensington, NSW, Australia.

The bacterial flagellar motor powers the rotation that propels the swimming bacteria. Rotational torque is generated by harnessing the flow of ions through ion channels known as stators which couple the energy from the ion gradient across the inner membrane to rotation of the rotor. Here, we used error-prone PCR to introduce single point mutations into the sodium-powered Vibrio alginolyticus/Escherichia coli chimeric stator PotB and selected for motors that exhibited motility in the presence of the sodium-channel inhibitor phenamil. Read More

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http://dx.doi.org/10.1111/mmi.14246DOI Listing

Calcineurin-dependent dephosphorylation of the transcription factor CrzA at specific sites controls conidiation, stress tolerance, and virulence of Aspergillus fumigatus.

Mol Microbiol 2019 Mar 29. Epub 2019 Mar 29.

Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA.

Calcium signaling through calcineurin and its major transcription factor (TF), CrzA, is integral to hyphal growth, stress response and virulence of the pathogenic fungus Aspergillus fumigatus, the leading etiology of invasive aspergillosis. Dephosphorylation of CrzA by calcineurin activates the TF, but the specific phosphorylation sites and their roles in the activation/inactivation mechanism are unknown. Mass spectroscopic analysis identified 20 phosphorylation sites, the majority of which were specific to filamentous fungi and distributed throughout the CrzA protein, with particular concentration in a serine-rich region N-terminal to the conserved DNA-binding domain (DBD). Read More

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http://dx.doi.org/10.1111/mmi.14254DOI Listing
March 2019
4 Reads

The developmental regulator MtrA binds GlnR boxes and represses nitrogen metabolism genes in Streptomyces coelicolor.

Mol Microbiol 2019 Mar 29. Epub 2019 Mar 29.

The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.

In Streptomyces, GlnR is an activator protein that activates nitrogen-assimilation genes under nitrogen-limiting conditions. However, less is known regarding the regulation of these genes under nitrogen-rich conditions. We determined that the developmental regulator MtrA represses nitrogen-assimilation genes in nitrogen-rich media and that it competes with GlnR for binding to GlnR boxes. Read More

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http://dx.doi.org/10.1111/mmi.14252DOI Listing

Defining the regulon of genes controlled by σ , a key regulator of the cell envelope stress response in Streptomyces coelicolor.

Mol Microbiol 2019 Mar 25. Epub 2019 Mar 25.

Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.

The extracytoplasmic function (ECF) σ factor, σ is a key regulator of the cell envelope stress response in Streptomyces coelicolor. Although its role in maintaining cell wall integrity has been known for over a decade, a comprehensive analysis of the genes under its control has not been undertaken. Here, using a combination of chromatin immunoprecipitation-sequencing (ChIP-seq), microarray transcriptional profiling and bioinformatic analysis, we attempt to define the σ regulon. Read More

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http://dx.doi.org/10.1111/mmi.14250DOI Listing

Detachment of the RNA degradosome from the inner membrane of Escherichia coli results in a global slowdown of mRNA degradation, proteolysis of RNase E and increased turnover of ribosome-free transcripts.

Mol Microbiol 2019 Mar 22. Epub 2019 Mar 22.

Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France.

The reason for RNase E attachment to the inner membrane is largely unknown. To understand the cell biology of RNA degradation, we have characterized a strain expressing RNase E lacking the membrane attachment site (cytoplasmic RNase E). Genome-wide data show a global slowdown in mRNA degradation. Read More

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http://dx.doi.org/10.1111/mmi.14248DOI Listing

CyaC, a redox-regulated adenylate cyclase of Sinorhizobium meliloti with a quinone responsive diheme-B membrane anchor domain.

Mol Microbiol 2019 Mar 22. Epub 2019 Mar 22.

Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg-University of Mainz, Becherweg 15, 55099, Mainz, Germany.

The nucleotide cyclase CyaC of Sinorhizobium meliloti is a member of class III adenylate cyclases (AC), a diverse group present in all forms of life. CyaC is membrane-integral by a hexahelical membrane domain (6TM) with the basic topology of mammalian ACs. The 6TM domain of CyaC contains a tetra-histidine signature that is universally present in the membrane anchors of bacterial diheme-B succinate-quinone oxidoreductases. Read More

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http://dx.doi.org/10.1111/mmi.14251DOI Listing
March 2019
1 Read

Systematic analysis of the Myxococcus xanthus developmental gene regulatory network supports posttranslational regulation of FruA by C-signaling.

Mol Microbiol 2019 Mar 20. Epub 2019 Mar 20.

Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.

Upon starvation Myxococcus xanthus undergoes multicellular development. Rod-shaped cells move into mounds in which some cells differentiate into spores. Cells begin committing to sporulation at 24-30 h poststarvation, but the mechanisms governing commitment are unknown. Read More

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http://dx.doi.org/10.1111/mmi.14249DOI Listing
March 2019
4.419 Impact Factor

SpbR overproduction reveals the importance of proteolytic degradation for cell pole development and chromosome segregation in Caulobacter crescentus.

Mol Microbiol 2019 Mar 19. Epub 2019 Mar 19.

Department of Molecular Biology, University of Wyoming, Laramie, WY, 82072, USA.

In most rod-shaped bacteria, DNA replication is quickly followed by chromosome segregation, when one of the newly duplicated centromeres moves across the cell to the opposite (or 'new') pole. Two proteins in Caulobacter crescentus, PopZ and TipN, provide directional cues at the new pole that guide the translocating chromosome to its destination. We show that centromere translocation can be inhibited by an evolutionarily conserved pole-localized protein that we have named SpbR. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1111/mmi.14247
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http://dx.doi.org/10.1111/mmi.14247DOI Listing
March 2019
7 Reads

Structural basis for interaction of DivIVA/GpsB proteins with their ligands.

Mol Microbiol 2019 Mar 18. Epub 2019 Mar 18.

Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, United Kingdom.

DivIVA proteins and their GpsB homologues are late cell division proteins found in Gram-positive bacteria. DivIVA/GpsB proteins associate with the inner leaflet of the cytosolic membrane and act as scaffolds for other proteins required for cell growth and division. DivIVA/GpsB proteins comprise an N-terminal lipid-binding domain for membrane association fused to C-terminal domains supporting oligomerization. Read More

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http://dx.doi.org/10.1111/mmi.14244DOI Listing
March 2019
1 Read

Analysis of a flagellar filament cap mutant reveals that HtrA serine protease degrades unfolded flagellin protein in the periplasm of Borrelia burgdorferi.

Mol Microbiol 2019 Mar 18. Epub 2019 Mar 18.

Philips Research Institute, Virginia Commonwealth University, Richmond, Virginia, 23298, USA.

Unlike external flagellated bacteria, spirochetes have periplasmic flagella (PF). Very little is known about how PF are assembled within the periplasm of spirochaetal cells. Herein, we report that FliD (BB0149), a flagellar cap protein (also named hook-associated protein 2), controls flagellin stability and flagellar filament assembly in the Lyme disease spirochete Borrelia burgdorferi. Read More

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http://dx.doi.org/10.1111/mmi.14243DOI Listing
March 2019
3 Reads
4.419 Impact Factor

RecBCD, SbcCD and ExoI process a substrate created by convergent replisomes to complete DNA replication.

Mol Microbiol 2019 Mar 18. Epub 2019 Mar 18.

Department of Biology, Portland State University, Portland, OR, 97201.

The accurate completion of DNA replication on the chromosome requires RecBCD and structure specific SbcCD ExoI nucleases. However, the substrates and mechanism by which this reaction occurs remains unknown. Here we show that these completion enzymes operate on plasmid substrates containing two replisomes, but are not required for plasmids containing one replisome. Read More

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http://dx.doi.org/10.1111/mmi.14242DOI Listing

Role of the global regulator Rex in control of NAD -regeneration in Clostridioides (Clostridium) difficile.

Mol Microbiol 2019 Mar 18. Epub 2019 Mar 18.

Pathogenesis of Bacterial Anaerobes Laboratory, Institut Pasteur, 75724, Paris, France.

For the human pathogen Clostridioides (also known as Clostridium) difficile, the ability to adapt to nutrient availability is critical for its proliferation and production of toxins during infection. Synthesis of the toxins is regulated by the availability of certain carbon sources, fermentation products and amino acids (e.g. Read More

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http://dx.doi.org/10.1111/mmi.14245DOI Listing
March 2019
4 Reads

A dual functional redox enzyme maturation protein for respiratory and assimilatory nitrate reductases in bacteria.

Mol Microbiol 2019 Mar 15. Epub 2019 Mar 15.

Centre for Molecular and Structural Biochemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.

Nitrate is available to microbes in many environments due to sustained use of inorganic fertilizers on agricultural soils and many bacterial and archaeal lineages have the capacity to express respiratory (Nar) and assimilatory (Nas) nitrate reductases to utilize this abundant respiratory substrate and nutrient for growth. Here, we show that in the denitrifying bacterium Paracoccus denitrificans, NarJ serves as a chaperone for both the anaerobic respiratory nitrate reductase (NarG) and the assimilatory nitrate reductase (NasC), the latter of which is active during both aerobic and anaerobic nitrate assimilation. Bioinformatic analysis suggests that the potential for this previously unrecognized role for NarJ in functional maturation of other cytoplasmic molybdenum-dependent nitrate reductases may be phylogenetically widespread as many bacteria contain both Nar and Nas systems. Read More

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http://dx.doi.org/10.1111/mmi.14239DOI Listing

Systematic analysis of Type I-E Escherichia coli CRISPR-Cas PAM sequences ability to promote interference and primed adaptation.

Mol Microbiol 2019 Mar 15. Epub 2019 Mar 15.

Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205, Russia.

CRISPR interference occurs when a protospacer recognized by the CRISPR RNA is destroyed by Cas effectors. In Type I CRISPR-Cas systems, protospacer recognition can lead to «primed adaptation» - acquisition of new spacers from in cis located sequences. Type I CRISPR-Cas systems require the presence of a trinucleotide protospacer adjacent motif (PAM) for efficient interference. Read More

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http://dx.doi.org/10.1111/mmi.14237DOI Listing
March 2019
3 Reads

Stringent response leads to continued cell division and a temporal re-start of DNA replication after initial shutdown in Vibrio cholerae.

Mol Microbiol 2019 Mar 15. Epub 2019 Mar 15.

LOEWE Center for Synthetic Microbiology - SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany.

Vibrio cholerae is an aquatic bacterium with the potential to infect humans and cause the cholera disease. While most bacteria have single chromosomes, the V. cholerae genome is encoded on two replicons of different size. Read More

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http://dx.doi.org/10.1111/mmi.14241DOI Listing

A non-coding RNA from the intercellular adhesion (ica) locus of Staphylococcus epidermidis controls polysaccharide intercellular adhesion (PIA)-mediated biofilm formation.

Mol Microbiol 2019 Mar 15. Epub 2019 Mar 15.

Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany.

Polysaccharide intercellular adhesin (PIA)-associated biofilm formation is mediated by the intercellular adhesin (ica) locus and represents a major pathomechanism of Staphylococcus epidermidis. Here, we report on a novel long non-coding (nc)RNA, named IcaZ, which is approximately 400 nucleotides in size. icaZ is located downstream of the ica repressor gene icaR and partially overlaps with the icaR 3' UTR. Read More

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http://dx.doi.org/10.1111/mmi.14238DOI Listing

Colistin heteroresistance in Enterobacter cloacae is regulated by PhoPQ-dependent 4-amino-4-deoxy-l-arabinose addition to lipid A.

Mol Microbiol 2019 Mar 15. Epub 2019 Mar 15.

Department of Biology, University of Texas at Arlington, Arlington, TX, USA.

The Enterobacter cloacae complex (ECC) consists of closely related bacteria commonly associated with the human microbiota. ECC are increasingly isolated from healthcare-associated infections, demonstrating that these Enterobacteriaceae are emerging nosocomial pathogens. ECC can rapidly acquire multidrug resistance to conventional antibiotics. Read More

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http://dx.doi.org/10.1111/mmi.14240DOI Listing
March 2019
5 Reads

Spatiotemporal control of FlgZ activity impacts Pseudomonas aeruginosa flagellar motility.

Mol Microbiol 2019 Mar 12. Epub 2019 Mar 12.

Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Inhoffenstr. 7, Braunschweig, 38124, Germany.

The c-di-GMP-binding effector protein FlgZ has been demonstrated to control motility in the opportunistic pathogen Pseudomonas aeruginosa and it was suggested that c-di-GMP-bound FlgZ impedes motility via its interaction with the MotCD stator. To further understand how motility is downregulated in P. aeruginosa and to elucidate the general control mechanisms operating during bacterial growth, we examined the spatiotemporal activity of FlgZ. Read More

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http://dx.doi.org/10.1111/mmi.14236DOI Listing

The plasmid-borne quinolone resistance protein QnrB, a novel DnaA-binding protein, increases the bacterial mutation rate by triggering DNA replication stress.

Mol Microbiol 2019 Mar 5. Epub 2019 Mar 5.

CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.

Bacterial antibiotic resistance, a global health threat, is caused by plasmid transfer or genetic mutations. Quinolones are important antibiotics, partially because they are fully synthetic and resistance genes are unlikely to exist in nature; nonetheless, quinolone resistance proteins have been identified. The mechanism by which plasmid-borne quinolone resistance proteins promotes the selection of quinolone-resistant mutants is unclear. Read More

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http://doi.wiley.com/10.1111/mmi.14235
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http://dx.doi.org/10.1111/mmi.14235DOI Listing
March 2019
6 Reads

A two-component regulatory system VfmIH modulates multiple virulence traits in Dickeya zeae.

Mol Microbiol 2019 Mar 2. Epub 2019 Mar 2.

Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China.

Bacterial pathogen Dickeya zeae strain EC1 produces antibiotics-like phytotoxins called zeamines, which are major virulence determinants encoded by the zms gene cluster. In this study, we identified a zeamine-deficient mutant with a Tn5 insertion in a gene designated as vfmI encoding a two-component system (TCS) sensor histidine kinase (HK), which is accompanied by vfmH encoding a response regulator (RR) at the same genetic locus. Domain analysis shows this TCS is analogous to the VfmIH of D. Read More

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http://dx.doi.org/10.1111/mmi.14233DOI Listing

Calcineurin responsive zinc-finger-1 binds to a unique promoter sequence to upregulate neuronal calcium sensor-1, whose interaction with MID-1 increases tolerance to calcium stress in Neurospora crassa.

Mol Microbiol 2019 Mar 2. Epub 2019 Mar 2.

Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, Assam, India.

We studied the molecular mechanism of neuronal calcium sensor-1 (NCS-1) signaling pathway for tolerance to Ca stress in Neurospora crassa. Increasing concentration of Ca increased the expression of ncs-1; however, the calcineurin inhibitor FK506 severely reduced ncs-1 mRNA transcript levels. Chromatin immunoprecipitation (ChIP) studies revealed that the transcription factor calcineurin responsive zinc finger-1 (CRZ-1) binds to the ncs-1 promoter, and CRZ-1 binding upregulated ncs-1 expression under high Ca concentrations. Read More

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http://dx.doi.org/10.1111/mmi.14234DOI Listing

Three Hfq-dependent small RNAs regulate flagellar motility in the fire blight pathogen Erwinia amylovora.

Mol Microbiol 2019 Mar 1. Epub 2019 Mar 1.

Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, USA.

Erwinia amylovora, the causative agent of fire blight disease of apple and pear trees, causes disease on flowers by invading natural openings at the base of the floral cup. To reach these openings, the bacteria use flagellar motility to swim from stigma tips to the hypanthium and through nectar. We have previously shown that the Hfq-dependent sRNAs ArcZ, OmrAB and RmaA regulate swimming motility in E. Read More

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http://dx.doi.org/10.1111/mmi.14232DOI Listing

A mutant bacteriophage evolved to infect resistant bacteria gained a broader host range.

Mol Microbiol 2019 Feb 27. Epub 2019 Feb 27.

Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem, Israel.

Bacteriophages (phages) are the most abundant entities in nature, yet little is known about their capacity to acquire new hosts and invade new niches. By exploiting the Gram-positive soil bacterium Bacillus subtilis (B. subtilis) and its lytic phage SPO1 as a model, we followed the coevolution of bacteria and phages. Read More

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http://dx.doi.org/10.1111/mmi.14231DOI Listing
February 2019
1 Read

Towards a systematic understanding of structure-function relationship of dimethylsulfoniopropionate-catabolizing enzymes.

Mol Microbiol 2019 Feb 25. Epub 2019 Feb 25.

School of Life Sciences, University of Warwick, Coventry, UK.

Each year, several million tons of dimethylsulfoniopropionate (DMSP) are produced by marine phytoplankton and bacteria as an important osmolyte to regulate their cellular osmosis. Microbial breakdown of DMSP to the volatile gas dimethylsulfide (DMS) plays an important role in global biogeochemical cycles of the sulphur element between land and the sea. Understanding the enzymes involved in the transformation of DMSP and DMS holds the key to a better understanding of oceanic DMSP cycles. Read More

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http://dx.doi.org/10.1111/mmi.14230DOI Listing
February 2019

Structural basis of transcriptional regulation by the HigA antitoxin.

Mol Microbiol 2019 Feb 21. Epub 2019 Feb 21.

Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA.

Bacterial toxin-antitoxin systems are important factors implicated in growth inhibition and plasmid maintenance. Type II toxin-antitoxin pairs are regulated at the transcriptional level by the antitoxin itself. Here, we examined how the HigA antitoxin regulates the expression of the Proteus vulgaris higBA toxin-antitoxin operon from the Rts1 plasmid. Read More

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http://dx.doi.org/10.1111/mmi.14229DOI Listing
February 2019

Growth-driven displacement of protein aggregates along the cell length ensures partitioning to both daughter cells in Caulobacter crescentus.

Mol Microbiol 2019 Feb 19. Epub 2019 Feb 19.

Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, 10691, Sweden.

All living cells must cope with protein aggregation, which occurs as a result of experiencing stress. In previously studied bacteria, aggregated protein is collected at the cell poles and is retained throughout consecutive cell divisions only in old pole-inheriting daughter cells, resulting in aggregation-free progeny within a few generations. In this study, we describe the in vivo kinetics of aggregate formation and elimination following heat and antibiotic stress in the asymmetrically dividing bacterium Caulobacter crescentus. Read More

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http://dx.doi.org/10.1111/mmi.14228DOI Listing
February 2019
1 Read

DksA-RNA polymerase interactions support new origin formation and DNA repair in Escherichia coli.

Mol Microbiol 2019 Feb 19. Epub 2019 Feb 19.

Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA.

The formation of new replication origins (cSDR) and repair of DNA double-strand breaks (DSBs) in E. coli share a commonality. We find that the two processes require the RNAP-associated factor, DksA. Read More

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http://doi.wiley.com/10.1111/mmi.14227
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http://dx.doi.org/10.1111/mmi.14227DOI Listing
February 2019
9 Reads

Toxic but tasty - temporal dynamics and network architecture of heme-responsive two-component signaling in Corynebacterium glutamicum.

Mol Microbiol 2019 Feb 15. Epub 2019 Feb 15.

Institute of Bio- und Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, 52425, Germany.

Heme is an essential cofactor and alternative iron source for almost all bacterial species but may cause severe toxicity upon elevated levels and consequently, regulatory mechanisms coordinating heme homeostasis represent an important fitness trait. A remarkable scenario is found in several corynebacterial species, e.g. Read More

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http://dx.doi.org/10.1111/mmi.14226DOI Listing
February 2019

Maintenance of the virulence plasmid in Shigella flexneri is influenced by Lon and two functional partitioning systems.

Mol Microbiol 2019 Feb 14. Epub 2019 Feb 14.

Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.

Members of the genus Shigella carry a large plasmid, pINV, which is essential for virulence. In Shigella flexneri, pINV harbours three toxin-antitoxin (TA) systems, CcdAB, GmvAT and VapBC that promote vertical transmission of the plasmid. Type II TA systems, such as those on pINV, consist of a toxic protein and protein antitoxin. Read More

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http://dx.doi.org/10.1111/mmi.14225DOI Listing
February 2019

Substrate-dependent cluster density dynamics of Corynebacterium glutamicum phosphotransferase system permeases.

Mol Microbiol 2019 Feb 12. Epub 2019 Feb 12.

Faculty of Biology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, Planegg-Martinsried, 82152, Germany.

Many bacteria take up carbohydrates by membrane-integral sugar specific phosphoenolpyruvate-dependent carbohydrate:phosphotransferase systems (PTS). Although the PTS is centrally involved in regulation of carbon metabolism in different bacteria, little is known about localization and putative oligomerization of the permease subunits (EII). Here, we analyzed localization of the fructose specific PtsF and the glucose specific PtsG transporters, as well as the general components EI and HPr from Corynebacterium glutamicum using widefield and single molecule localization microscopy. Read More

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http://dx.doi.org/10.1111/mmi.14224DOI Listing
February 2019

Bacterial NHEJ: a never ending story.

Mol Microbiol 2019 Feb 12. Epub 2019 Feb 12.

Université de Lorraine, INRA, DynAMic, Nancy, F-54000, France.

Double-strand breaks (DSBs) are the most detrimental DNA damage encountered by bacterial cells. DBSs can be repaired by homologous recombination thanks to the availability of an intact DNA template or by Non-Homologous End Joining (NHEJ) when no intact template is available. Bacterial NHEJ is performed by sets of proteins of growing complexity from Bacillus subtilis and Mycobacterium tuberculosis to Streptomyces and Sinorhizobium meliloti. Read More

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http://dx.doi.org/10.1111/mmi.14218DOI Listing
February 2019
2 Reads

The meiosis-specific APC activator FgAMA1 is dispensable for meiosis but important for ascosporogenesis in Fusarium graminearum.

Mol Microbiol 2019 Feb 11. Epub 2019 Feb 11.

State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.

Ascospores are the primary inoculum in Fusarium graminearum. Interestingly, 70 of its genes have premature stop codons (PSC) and require A-to-I editing during sexual reproduction to encode full-length proteins, including the ortholog of yeast Ama1, a meiosis-specific activator of APC/C. In this study, we characterized the function of FgAMA1 and its PSC editing. Read More

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http://dx.doi.org/10.1111/mmi.14219DOI Listing
February 2019

Tic22 from Anabaena sp. PCC 7120 with holdase function involved in outer membrane protein biogenesis shuttles between plasma membrane and Omp85.

Mol Microbiol 2019 Feb 11. Epub 2019 Feb 11.

Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Frankfurt am Main, Germany.

β-barrel-shaped outer membrane proteins (OMPs) ensure regulated exchange of molecules across the cell-wall of Gram-negative bacteria. They are synthesized in the cytoplasm and translocated across the plasma membrane via the SEC translocon. In the periplasm, several proteins participate in the transfer of OMPs to the outer membrane-localized complex catalyzing their insertion. Read More

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http://dx.doi.org/10.1111/mmi.14222DOI Listing
February 2019
6 Reads

The master quorum-sensing regulators LuxR/HapR directly interact with the alpha subunit of RNA polymerase to drive transcription activation in Vibrio harveyi and Vibrio cholerae.

Mol Microbiol 2019 Feb 11. Epub 2019 Feb 11.

Department of Biology, Indiana University, Bloomington, IN, 47405, USA.

In Vibrio species, quorum sensing controls gene expression for numerous group behaviors, including bioluminescence production, biofilm formation, virulence factor secretion systems, and competence. The LuxR/HapR master quorum-sensing regulators activate expression of hundreds of genes in response to changes in population densities. The mechanism of transcription activation by these TetR-type transcription factors is unknown, though LuxR DNA binding sites that lie in close proximity to the -35 region of the promoter are required for activation at some promoters. Read More

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http://dx.doi.org/10.1111/mmi.14223DOI Listing
February 2019

Increased drug permeability of a stiffened mycobacterial outer membrane in cells lacking MFS transporter Rv1410 and lipoprotein LprG.

Mol Microbiol 2019 Feb 11. Epub 2019 Feb 11.

Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland.

The major facilitator superfamily transporter Rv1410 and the lipoprotein LprG (Rv1411) are encoded by a conserved two-gene operon and contribute to virulence in Mycobacterium tuberculosis. Rv1410 was originally postulated to function as a drug efflux pump, but recent studies suggested that Rv1410 and LprG work in concert to insert triacylglycerides and lipoarabinomannans into the outer membrane. Here, we conducted microscopic analyses of Mycobacterium smegmatis lacking the operon and observed a cell separation defect, while surface rigidity measured by atomic force microscopy was found to be increased. Read More

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http://dx.doi.org/10.1111/mmi.14220DOI Listing
February 2019
5 Reads

Division-site localization of RodZ is required for efficient Z ring formation in Escherichia coli.

Mol Microbiol 2019 Feb 11. Epub 2019 Feb 11.

Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan.

Bacteria such as Escherichia coli must coordinate cell elongation and cell division. Elongation is regulated by an elongasome complex containing MreB actin and the transmembrane protein RodZ, which regulates assembly of MreB, whereas division is regulated by a divisome complex containing FtsZ tubulin. These complexes were previously thought to function separately. Read More

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http://dx.doi.org/10.1111/mmi.14217DOI Listing
February 2019

Modulation of calcineurin activity in Aspergillus nidulans: the roles of high magnesium concentrations and of transcriptional factor CrzA.

Mol Microbiol 2019 Feb 11. Epub 2019 Feb 11.

Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CIB), CSIC, Ramiro de Maeztu, 9, Madrid, 28040, Spain.

A proper response to elevated extracellular calcium levels helps to most organisms to keep this secondary messenger under strict control, thereby preventing inadequate activation or inhibition of many regulatory activities into cells. In fungi, the calcineurin responsive zinc-finger Crz1/CrzA transcription factor transduces calcium signaling to gene expression. In Aspergillus nidulans, absence of CrzA activity leads to alkaline pH sensitivity and loss of tolerance to high levels of extracellular calcium. Read More

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http://dx.doi.org/10.1111/mmi.14221DOI Listing
February 2019
5 Reads

Deciphering the essentiality and function of the anti-σ factors in Bacillus subtilis.

Mol Microbiol 2019 Feb 4. Epub 2019 Feb 4.

Department of Microbiology, Cornell University, Ithaca, NY, 14853-8101, USA.

Bacteria use alternative sigma factors to adapt to different growth and stress conditions. The Bacillus subtilis extracytoplasmic function sigma factor SigM regulates genes for cell wall synthesis and is crucial for maintaining cell wall homeostasis under stress conditions. The activity of SigM is regulated by its anti-sigma factor, YhdL, and the accessory protein YhdK. Read More

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http://dx.doi.org/10.1111/mmi.14216DOI Listing
February 2019
1 Read

Controlling chronic Pseudomonas aeruginosa infections by strategically interfering with the sensory function of SagS.

Mol Microbiol 2019 Feb 2. Epub 2019 Feb 2.

Department of Biological Sciences, Binghamton University, Binghamton, NY, 13902, USA.

The hybrid sensor SagS plays a central role in the formation of Pseudomonas aeruginosa biofilms, by enabling the switch from the planktonic to the biofilm mode of growth and by facilitating the transition of biofilm cells to a highly tolerant state. In this study, we examined the importance of the SagS key amino acid residues associated with biofilm formation (L154) and antibiotic tolerance (D105) in P. aeruginosa virulence. Read More

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http://dx.doi.org/10.1111/mmi.14215DOI Listing
February 2019
1 Read

Class II contact-dependent growth inhibition (CDI) systems allow for broad-range cross-species toxin delivery within the Enterobacteriaceae family.

Mol Microbiol 2019 Apr 18;111(4):1109-1125. Epub 2019 Mar 18.

Department of Cell and Molecular Biology, Uppsala University, Uppsala, 75124, Sweden.

Contact-dependent growth inhibition (CDI) allows bacteria to recognize kin cells in mixed bacterial populations. In Escherichia coli, CDI mediated effector delivery has been shown to be species-specific, with a preference for the own strain over others. This specificity is achieved through an interaction between a receptor-binding domain in the CdiA protein and its cognate receptor protein on the target cell. Read More

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http://dx.doi.org/10.1111/mmi.14214DOI Listing