Article
Microbiology
Thomas D. Watts, Daouda A. K. Traore, Sarah C. Atkinson, Carmen Lao, Natalie Caltabiano, Julian Rood, Vicki Adams
Summary: The compatibility of conjugative toxin plasmids in Clostridium perfringens is mediated by their ParMRC-like partitioning systems, with plasmids from the same family being incompatible and plasmids from different families being compatible.
Article
Biochemistry & Molecular Biology
Steven J. Hancock, Minh-Duy Phan, Leah W. Roberts, Thu Ngoc Minh Vu, Patrick N. A. Harris, Scott A. Beatson, Mark A. Schembri
Summary: Incompatibility group C (IncC) plasmids are large, broad host range plasmids that spread genes conferring resistance to antibiotics. Recent studies have identified novel IncC conjugation genes, including dtrJ, which has been examined in detail. The role of DtrJ in DNA transfer of IncC plasmids during conjugation has been defined through this work.
MOLECULAR MICROBIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Karina Yui Eto, Stephen M. Kwong, Patrick T. LaBreck, Jade E. Crow, Daouda A. K. Traore, Nipuna Parahitiyawa, Heather M. Fairhurst, D. Scott Merrell, Neville Firth, Charles S. Bond, Joshua P. Ramsay
Summary: The study investigates the horizontal transfer mechanism of plasmids in Staphylococcus aureus, finding that plasmids related to pWBG749 are mobilizable due to the presence of oriT sequences. The research shows that SmpO proteins in pWBG749 predominantly form tetramers and bind specific sites within oriT sequences, with a substitution in pWBG749 being able to switch oriT-binding specificity. In vivo experiments demonstrate that the substitution broadens the mobilized oriT subtypes, suggesting a potential evolutionary intermediate that could facilitate a switch between oriT specificities.
NUCLEIC ACIDS RESEARCH
(2021)
Article
Microbiology
Jorge Val-Calvo, Andres Miguel-Arribas, Fernando Freire, David Abia, Ling Juan Wu, Wilfried J. J. Meijer
Summary: Conjugation is a process of transferring conjugative DNA elements from a donor to a recipient cell through a connecting channel, with clinical relevance in spreading antibiotic resistance and virulence genes. The stability of transferring DNA into a new host requires the conversion of single-stranded DNA into double-stranded DNA and inhibition of host defense mechanisms. Establishment genes play a critical role in rapid and transiently inactivating the host defense mechanisms to facilitate the successful transfer of DNA.
Article
Microbiology
Yue Wang, Zhigang Yu, Pengbo Ding, Ji Lu, Uli Kluemper, Aimee K. Murray, William H. Gaze, Jianhua Guo
Summary: Non-antibiotic pharmaceuticals can promote antibiotic resistance transfer in microbial communities, potentially increasing the risk of antibiotic resistance dissemination in the environment.
Article
Biotechnology & Applied Microbiology
Rebecca L. Dineen, Christophe Penno, Philip Kelleher, Maxence J. B. Bourin, Mary O'Connell-Motherway, Douwe van Sinderen
Summary: RepB is identified as the replicative initiator of pMP7017, being capable of autonomous replication. The repeat sequence binding region is essential for efficient replication. pMP7017 is suggested to be an iteron-regulated plasmid under strict auto-regulatory control.
MICROBIAL BIOTECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Andres Miguel-Arribas, Jorge Val-Calvo, Cesar Gago-Cordoba, Jose M. Izquierdo, David Abia, Ling Juan Wu, Jeff Errington, Wilfried J. J. Meijer
Summary: This study describes a novel bipartite antitermination system, named conAn, prevalent among conjugative elements from Gram-positive bacteria. The system consists of a large RNA element exerting antitermination and a protein serving as a processivity factor. In addition to allowing coordinated expression of long operons, these systems also enable differential gene expression within an operon and may contribute to strict regulation of conjugation genes by minimizing the effects of spurious transcription.
NUCLEIC ACIDS RESEARCH
(2021)
Article
Biochemistry & Molecular Biology
Joshua P. Ramsay, Tahlia R. Bastholm, Callum J. Verdonk, Dinah D. Tambalo, John T. Sullivan, Liam K. Harold, Beatrice A. Panganiban, Elena Colombi, Benjamin J. Perry, William Jowsey, Calum Morris, Michael F. Hynes, Charles S. Bond, Andrew D. S. Cameron, Christopher K. Yost, Clive W. Ronson
Summary: The horizontal transfer of ICEMlSym (R7A) can cause non-symbiotic Mesorhizobium spp. to become nitrogen-fixing legume symbionts. A subpopulation of Mesorhizobium japonicum R7A called R7A* is epigenetically primed for quorum sensing and horizontal transfer, maintained in laboratory culture. The epigenetic maintenance of the R7A* state requires ICEMlSym (R7A)-encoded copies of both qseC and qseC2, forming a stable epigenetic switch that controls qseM transcription and primes a subpopulation of R7A cells for quorum sensing and horizontal transfer.
NUCLEIC ACIDS RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Jiahui Wu, Nina Svensen, Wenjiao Song, Hyaeyeong Kim, Sulei Zhang, Xing Li, Samie R. Jaffrey
Summary: DNA and RNA can self-assemble into various structures, and there are methods available to achieve RNA self-assembly in cells. The use of dimeric aptamers allows the creation of RNA and RNA-protein assemblies in cells. These studies provide an approach for inducing RNA self-assembly, demonstrate that proteins can be recruited to RNA assemblies to genetically encode intracellular RNA-protein assemblies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Biochemistry & Molecular Biology
Guilherme de Castro, Dennis J. Worm, Grzegorz J. Grabe, Fiona C. Rowan, Lucy Haggerty, Ana L. de la Lastra, Oana Popescu, Sophie Helaine, Anna Barnard
Summary: In this study, a novel method was developed to produce recombinant bacterial toxin Doc, and antitoxin-mimicking peptides were used to investigate the mechanism by which its cognate antitoxin Phd neutralizes the activity of Doc. The study provides insights into the molecular detail of the Phd-Doc relationship and identifies key principles for the development of chemical tools to study and therapeutically interrogate this important class of protein-protein interactions.
ACS CHEMICAL BIOLOGY
(2022)
Article
Multidisciplinary Sciences
Haiqing Sheng, Sarah Wu, Yansong Xue, Wei Zhao, Allan B. Caplan, Carolyn J. Hovde, Scott A. Minnich
Summary: In this study, self-transmissible plasmids carrying CRISPR-Cas9 systems were engineered to target pathogenic E. coli and Salmonella. In vitro experiments demonstrated the ability of these plasmids to selectively kill specific strains of E. coli and Salmonella, as well as reduce the number of antibiotic-resistant bacteria. Mouse models showed significant reductions of intestinal pathogens using this method.
Article
Microbiology
Sofia Mindlin, Olga Maslova, Alexey Beletsky, Varvara Nurmukanova, Zhiyong Zong, Andrey Mardanov, Mayya Petrova
Summary: The study provides a detailed characterization of a newly discovered family of multi-drug resistant mega-plasmids in Acinetobacter species, showing their ability to spread among different species and mobilize other mobilizable plasmids efficiently. It also reveals a significant presence of mega-plasmids in natural Acinetobacter strains, with a clear correlation between living conditions and plasmid structure. The findings highlight the key role of these mega-plasmids in the dissemination of multi-drug resistance in Acinetobacter species.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Stefan Kreida, Akihiro Narita, Matthew D. Johnson, Elitza I. Tocheva, Anath Das, Debnath Ghosal, Grant J. Jensen
Summary: The horizontal transfer of oncogenic DNA by Agrobacterium tumefaciens causes crown gall disease in plants. This transfer is mediated by the VirB/D4 type 4 secretion system (T4SS), which assembles an extracellular filament, the T-pilus, and is involved in mating pair formation. A 3 A cryo-EM structure of the T-pilus was obtained, revealing its stoichiometric assembly of VirB2 major pilin and phosphatidylglycerol (PG) phospholipid with 5-start helical symmetry. The T-pilus lumen is positively charged, raising questions about its role in ssDNA transfer.
Review
Chemistry, Inorganic & Nuclear
Xin-Xin Peng, Xiaoling Qin, You Qin, Yuanhang Xiang, Guo-Jun Zhang, Fan Yang
Summary: This review summarizes recent progress in bioprobes-mediated exosomal biosensing, covering the transition from extravesicular to intravesicular analysis, from solid sensor surface to solution phase, and from simplex to multiplexing detection. The review highlights the use of bioprobes, including one-dimensional to three-dimensional structures and antibodies to functional nucleic acids, for the recognition, capture, and detection of exosomal biomarkers.
COORDINATION CHEMISTRY REVIEWS
(2022)
Article
Materials Science, Multidisciplinary
Z. Zhang, T. He, J. Zhao, G. Liu, Z. L. Wang, C. Zhang
Summary: The study discusses the coupling effects of frictional heating, triboelectrification, and semiconductor materials. Rubbing a metal on a semiconductor can lead to the generation of thermoelectric and tribovoltaic effects, resulting in the movement of majority carriers and the generation of direct current. The output is influenced by factors such as frictional energy, temperature difference, velocity, and pressure, demonstrating the potential for multi-source energy harvesting.
MATERIALS TODAY PHYSICS
(2021)
Article
Gastroenterology & Hepatology
Theresa M. Greimel, Laura Stampfer, Eva Leitner, Sabine Kienesberger, Ellen L. Zechner, Michael Bozic, Gabriel E. Wagner, Katrin Unterhauser, Maksym Kitsera, Almuthe C. Hauer, Gregor Gorkiewicz, Philipp Wurm, Francesco Valitutti, Christoph Hogenauer, Karl Martin Hoffmann
Summary: Over 70% of healthy infants were found to be colonized with K oxytoca, but toxin levels were below detection level and only half of the isolates produced toxin in vitro. This has important implications for future disease association studies.
JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION
(2022)
Article
Microbiology
Norbert Izghirean, Claudia Waidacher, Clemens Kittinger, Miriam Chyba, Guenther Koraimann, Brigitte Pertschy, Gernot Zarfel
Summary: Tigecycline, a last-resort antibiotic, and tetracycline inhibit translation by binding to the 30S ribosomal subunit. Mutations in ribosomal RNA and proteins, particularly S10 V57 mutations, contribute to resistance in E. coli. However, additional mutations are necessary to reach high-level tigecycline resistance, with S10 mutations causing growth defects and alterations in antibiotic binding.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Nagender Ledala, Mishika Malik, Karim Rezaul, Sara Paveglio, Anthony Provatas, Aaron Kiel, Melissa Caimano, Yanjiao Zhou, Jonathan Lindgren, Kristyna Krasulova, Peter Illes, Zdenek Dvorak, Sandhya Kortagere, Sabine Kienesberger, Amar Cosic, Lisa Poeltl, Ellen L. Zechner, Subho Ghosh, Sridhar Mani, Justin D. Radolf, Adam P. Matson
Summary: In this study, it was shown that bacterial indole acts as a multifunctional mitigator of pathogenicity by suppressing toxin production, enhancing conversion of tilimycin to tilivalline, and activating PXR.
Article
Microbiology
Gerardo Carranza, Tamara Menguiano, Fernando Valenzuela-Gomez, Yolanda Garcia-Cazorla, Elena Cabezon, Ignacio Arechaga
Summary: Bacterial conjugation is the main mechanism for horizontal gene transfer and plays a major role in the dissemination of antibiotic resistance genes. Research has shown that multiple copies of conjugative plasmids are transferred during mating, and fluorescent protein fusions can be used to track the localization of ATPases involved in conjugation.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Charles Coluzzi, Maria Pilar Garcillan-Barcia, Fernando de la Cruz, Eduardo P. C. Rocha
Summary: Conjugation drives the horizontal transfer of adaptive traits across prokaryotes, and the evolution of plasmid mobility is frequent and shapes the patterns of gene flow in bacteria and the ecology of plasmids.
MOLECULAR BIOLOGY AND EVOLUTION
(2022)
Article
Construction & Building Technology
Lukas G. Briendl, Cyrill Grengg, Bernhard Mueller, Guenther Koraimann, Florian Mittermayr, Patrick Steiner, Isabel Galan
Summary: In this study, the fast pH changes in ordinary Portland cement pastes caused by the addition of a setting accelerator were monitored with optical pH sensors. The results demonstrated the ability of this novel method to determine pH with high temporal resolution. Fluorescence imaging was also used to assess the distribution of the accelerator within the cement paste. These methods are important for predicting and assessing the effects of chemical admixtures on cement hydration progress.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Microbiology
Hattie E. Webb, Kaitlin A. Tagg, Justin Y. Kim, Elizabeth A. Miller, Timothy J. Johnson, Arancha Penil-Celis, Fernando de la Cruz, Jason P. Folster
Summary: This study provides five Salmonella Reading reference genomes collected from US patients between 2016 and 2018, offering important data for further investigation of the outbreak linked to raw turkey products.
MICROBIOLOGY RESOURCE ANNOUNCEMENTS
(2022)
Article
Biochemistry & Molecular Biology
Valentin Quebre, Irene del Campo, Ana Cuevas, Patricia Siguier, Jerome Rech, Phan Thai Nguyen Le, Bao Ton-Hoang, Francois Cornet, Jean-Yves Bouet, Gabriel Moncalian, Fernando de la Cruz, Catherine Guynet
Summary: This study determined the crystal structure of the conserved N-terminal domain of StbA, revealing the molecular basis of StbA and its role in plasmid segregation.
JOURNAL OF MOLECULAR BIOLOGY
(2022)
Article
Microbiology
Sabine Kienesberger, Amar Cosic, Maksym Kitsera, Sandra Raffl, Marlene Hiesinger, Eva Leitner, Bettina Halwachs, Gregor Gorkiewicz, Ronald A. Glabonjat, Georg Raber, Christian Lembacher-Fadum, Rolf Breinbauer, Stefan Schild, Ellen L. Zechner
Summary: The enterotoxin tilimycin produced by gut-resident Klebsiella species can alter gut microbiota composition, induce mutational evolution and drive the emergence of antibiotic resistance in mice. Tilimycin reduces the microbial richness in the gut, promotes mutations in opportunistic pathogens, and contributes to the development of antibiotic resistance.
NATURE MICROBIOLOGY
(2022)
Article
Microbiology
Hattie E. Webb, Justin Y. Kim, Kaitlin A. Tagg, Fernando de la Cruz, Arancha Penil-Celis, Beth Tolar, Zachary Ellison, Colin Schwensohn, Joshua Brandenburg, Megin Nichols, Jason P. Folster
Summary: This study reports 18 Salmonella Hadar genomes from samples collected from patients in the United States between 2014 and 2020, addressing the lack of reference genomes for this serotype.
MICROBIOLOGY RESOURCE ANNOUNCEMENTS
(2022)
Article
Biochemistry & Molecular Biology
Raul Fernandez-Lopez, Raul Ruiz, Irene del Campo, Lorena Gonzalez-Montes, D. Roeland Boer, Fernando de la Cruz, Gabriel Moncalian
Summary: Some transcription factors prefer binding to DNA motifs with direct or inverted sequence repeats based on structural constraints. Most prokaryotic regulators form symmetric oligomers that require operators with a dyad structure. Breaking the internal symmetry is necessary for binding to direct repeats, a property mostly seen in a few regulators from the AraC family. The KorA family of transcriptional repressors, involved in plasmid propagation and stability, includes members that form symmetric dimers and recognize inverted repeats. Our structural analyses reveal that ArdK, a member of this family, can form a symmetric dimer similar to KorA, but it binds to direct sequence repeats as a non-symmetric dimer by rotating one of the helix-turn-helix domains by 180 degrees. We also confirmed ArdK's affinity for an inverted repeat, which surprisingly is also recognized by a non-symmetrical dimer. Our findings suggest that structural flexibility at different positions in the dimerization interface restricts transcription factors to bind to DNA sequences with one of these two alternative DNA topologies.
NUCLEIC ACIDS RESEARCH
(2022)
Article
Construction & Building Technology
Marlene Sakoparnig, Isabel Galan, Wolfgang Kusterle, Benedikt Lindlar, Guenther Koraimann, Thomas Angerer, Florian R. Steindl, Lukas G. Briendl, Sebastian Jehle, Johannes Flotzinger, Joachim Juhart, Florian Mittermayr
Summary: This study investigates the dosing of accelerator in the wet-mix shotcrete process and finds that pressure fluctuations lead to changes in the accelerator to concrete ratio. The presence of accelerator layers, as shown by fluorescent tracer distribution, can have detrimental effects on shotcrete properties.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Chemistry, Medicinal
Cristina Gonzalez-Fernandez, Christoph Ohlknecht, Matthias Diem, Yerko Escalona, Eugenio Bringas, Gabriel Moncalian, Chris Oostenbrink, Inmaculada Ortiz
Summary: The development of new strategies to combat Gram-negative bacterial infections, particularly those resistant to antibiotics, is crucial due to the global increase in antibiotic resistance. This study focuses on the use of extracorporeal blood cleansing devices with affinity sorbents for capturing bacterial lipopolysaccharide (LPS), which stimulates an exacerbated immune response during infection. Molecular dynamics simulations were conducted to investigate the interaction mechanism between an anti-LPS factor (ALF) isoform 3 from Penaeus monodon (AL3) and lipid A (LA, a component of LPS). The results revealed the binding mechanism and key interacting residues, which can guide the design of LPS-sequestrating molecules for blood detoxification.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Biochemistry & Molecular Biology
Fernando Valenzuela-Gomez, Ignacio Arechaga, Elena Cabezon
Summary: Bacterial conjugation is the main mechanism for the dissemination of antibiotic resistance genes. In this study, nanopore technology was used to investigate the unfolding states of the relaxase-DNA complex during translocation. The unfolding pathway of the relaxase depends on the tyrosine residue involved in conjugative DNA binding. This study provides new insights for applying nanopore sensing to study protein secretion.
NUCLEIC ACIDS RESEARCH
(2023)
Article
Cell Biology
Lisa Poltl, Maksym Kitsera, Sandra Raffl, Stefan Schild, Amar Cosic, Sabine Kienesberger, Katrin Unterhauser, Georg Raber, Christian Lembacher-Fadum, Rolf Breinbauer, Gregor Gorkiewicz, Carlos Sebastian, Gerald Hoefler, Ellen L. Zechner
Summary: The DNA-alkylating metabolite tilimycin is a microbial genotoxin that causes colitis in individuals carrying til+ Klebsiella spp. Intestinal stem cells are affected by tilimycin-induced DNA damage, leading to genetic aberrations and increased disease susceptibility in the colon. The presence of tilimycin-producing Klebsiella results in higher frequencies and more mutations per individual compared to non-producing mutants.