Article
Ecology
Elisa T. Granato, William P. J. Smith, Kevin R. Foster
Summary: Bacteria can collectively defend themselves against attacks from other strains using the T6SS, and the production of EPS can serve as a collective defense mechanism to protect both EPS-producing and non-producing cells. This has been confirmed by agent-based simulations and experiments.
Review
Biochemistry & Molecular Biology
Julia Sanchez-Garrido, David Ruano-Gallego, Jyoti S. Choudhary, Gad Frankel
Summary: Recent studies have shown that T3SS effectors interact with each other in the host, revealing their interdependency and context-dependent essentiality, which is of great significance for understanding the pathogenesis of the pathogens.
TRENDS IN MICROBIOLOGY
(2022)
Article
Cell Biology
Le Tang, Shuqi Dong, Nadia Rasheed, Hao Weng Wu, Ningkun Zhou, Huadong Li, Meilin Wang, Jun Zheng, Jun He, William Chong Hang Chao
Summary: The study reveals that Rhs proteins, an ancient giant protein fold, can act as polymorphic toxins in interbacterial competitions through the ABC complex or T6SS. The research on Vibrio parahaemolyticus shows that RhsP-dependent prey targeting requires T6SS2 and RhsP can self-cleave into fragments, with the toxic C-terminal fragment binding to VgrG2. The alternative conformation of VIR, encapsulated inside the Rhs b barrel structure, triggers RhsP dimerization and plays a significant role in prey targeting.
Article
Biotechnology & Applied Microbiology
Yang Cui, Tong-Tong Pei, Xiaoye Liang, Hao Li, Hao-Yu Zheng, Tao Dong
Summary: The T6SS is a powerful and versatile protein delivery system. In this study, the researchers successfully assembled the T6SS of Aeromonas dhakensis in Escherichia coli, demonstrating its ability to deliver proteins and exhibit antimicrobial activities. This engineered T6SS provides E. coli with the capability to deliver protein cargos into a wide range of cells.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Microbiology
Boris Taillefer, Julien F. Giraud, Eric Cascales
Summary: Polymicrobial communities are influenced by interactions between different species, including the competition mediated by the type VI secretion system (T6SS). This study shows that the synthesis, assembly, contraction, and disassembly of T6SS do not result in a significant growth cost for enteroaggregative Escherichia coli.
JOURNAL OF BACTERIOLOGY
(2023)
Article
Microbiology
Chih-Feng Wu, Alexandra J. Weisberg, Edward W. Davis, Lin Chou, Surtaz Khan, Erh-Min Lai, Chih-Horng Kuo, Jeff H. Chang
Summary: The T6SS is used by many Gram-negative bacteria for interbacterial competition, with diverse strains of agrobacteria showing different patterns of T6SS expression and enrichment in specific sets of T6SS loci. Diversification is driven by the reshuffling of entire loci and fragments, but constrained by the maintenance of specific gene subtypes.
Article
Immunology
Mariana Izquierdo, Joaquin Lopez, Pablo Gallardo, Roberto M. Vidal, Juan C. Ossa, Mauricio J. Farfan
Summary: This study evaluated the role of Citrobacter werkmanii and Escherichia albertii in the virulence of Shiga toxin-producing and enteroaggregative Escherichia coli pathotypes, revealing their effects on gene expression and toxin secretion.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2022)
Article
Multidisciplinary Sciences
Patricia Bernal, R. Christopher D. Furniss, Selina Fecht, Rhoda C. Y. Leung, Livia Spiga, Despoina A. Mavridou, Alain Filloux
Summary: The T6SS is a nanomachine primarily involved in interbacterial competition, with TssA being a key component for its assembly. Researchers have found unexpected diversity in TssA proteins, with a short form and a long form existing. The discovery of structural components that interact with short TssA proteins sheds light on the mechanisms for T6SS assembly and functioning.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Medicinal
Aoi Kimishima, Daichi Hagimoto, Masako Honsho, Yoshihiro Watanabe, Masato Iwatsuki, Hayama Tsutsumi, Yuki Inahashi, Kamrun Naher, Kazunari Sakai, Asaomi Kuwae, Akio Abe, Yukihiro Asami
Summary: Aurodox, originally discovered in 1972 as an antibacterial compound, has been identified as a specific inhibitor of the bacterial type III secretion system (T3SS) in enteropathogenic Escherichia coli (EPEC). This study synthesized 15 derivatives of aurodox and evaluated their inhibitory activity against EPEC T3SS and antibacterial activity. One derivative showed high selectivity for T3SS inhibition without exhibiting antibacterial activity, indicating a distinct target for T3SS inhibition compared to antibacterial activity.
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2022)
Article
Biotechnology & Applied Microbiology
Xiaoye Liang, Tong-Tong Pei, Zeng-Hang Wang, Weiliang Xiong, Li-Li Wu, Ping Xu, Shuangjun Lin, Tao G. Dong
Summary: The Type VI Secretion System (T6SS) is utilized by Gram-negative bacteria for interspecies interaction. This study identified a lysozyme-like effector TseP in Aeromonas dhakensis, showcasing its cell wall-lysing activities and T6SS dependency. Inactivating TseP and two other effectors led to the creation of a detoxified T6SS-active strain for potential protein delivery to various recipient cells.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Microbiology
Xiaoye Liang, Hao-Yu Zheng, Ya-Jie Zhao, Yi-Qiu Zhang, Tong-Tong Pei, Yang Cui, Ming-Xuan Tang, Ping Xu, Tao Dong
Summary: Multiple paralogs of the cone-shaped PAAR are found in gram-negative bacteria, but their necessity for T6SS assembly remains unclear. This study reveals a conditional requirement for PAAR in T6SS functions and suggests a core-auxiliary relationship among different PAAR-VgrG modules.
JOURNAL OF BACTERIOLOGY
(2023)
Article
Microbiology
Sophie A. Howard, R. Christopher D. Furniss, Dora Bonini, Himani Amin, Patricia Paracuellos, David Zlotkin, Tiago R. D. Costa, Asaf Levy, Despoina A. I. Mavridou, Alain Filloux
Summary: The T6SS is a bacterial nanoscale weapon that delivers toxins into prey and plays a key role in the arms race between organisms. By using Hcp as bait, researchers identified uncharacterized toxins and investigated the role of Hcp in the T6SS mechanism.
Review
Microbiology
Xiaobing Yang, Hai Liu, Yanxiong Zhang, Xihui Shen
Summary: The type VI secretion system (T6SS) in gram-negative bacteria has multiple functions, including the newly discovered function of metal ion transport. The review provides a summary of identified T6SS functions and discusses the features and regulation of metal ion transport mediated by T6SS.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Infectious Diseases
Angelina A. Kislichkina, Nikolay N. Kartsev, Yury P. Skryabin, Angelika A. Sizova, Maria E. Kanashenko, Marat G. Teymurazov, Ekaterina S. Kuzina, Alexander G. Bogun, Nadezhda K. Fursova, Edward A. Svetoch, Ivan A. Dyatlov
Summary: Hybrid diarrheagenic E. coli strains with genetic markers from different pathotypes have emerged as a public health concern. The most well-known hybrid strain, E. coli O104:H4, caused a serious outbreak of acute gastroenteritis and hemolytic uremic syndrome (HUS) in Germany in 2011. A recent case of HUS intestinal infection was reported in St. Petersburg, Russia, with the E. coli strain SCPM-O-B-9427, which shares similarities with other related strains.
Review
Biochemistry & Molecular Biology
Amit Meir, Kevin Mace, Yogesh Vegunta, Sunanda M. Williams, Gabriel Waksman
Summary: This review provides an update on recent advances in substrate recruitment and delivery by recruitment platforms associated with Type III, IV, and VI secretion systems in gram-negative bacteria.
TRENDS IN MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Brice Barbat, Badreddine Douzi, Rome Voulhoux
Summary: Bacteria have various mechanisms for exchanging and communicating with their environment, including the use of secretins to actively transport large substances to the bacterial surface. Secretins are pore-forming complexes in the outer membrane of Gram-negative bacteria that translocate folded proteins, fibers, virus particles, or DNA. Recent 3D structures have provided insights into the translocation mechanisms of secretins.
Article
Biochemistry & Molecular Biology
Thi Thu Hang Le, Christine Kellenberger, Marie Boyer, Pierre Santucci, Nicolas Flaugnatti, Eric Cascales, Alain Roussel, Stephane Canaan, Laure Journet, Christian Cambillau
Summary: This study identifies and characterizes a phospholipase effector (Tle3) and its immunity protein (Tli3) from adherent-invasive Escherichia coli (AIEC). It demonstrates that purified Tle3 has phospholipase A1 activity and its toxicity is neutralized by Tli3. The study also shows that Tle3 interacts with VgrG(AIEC) protein, indicating a strong interaction between them.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biochemistry & Molecular Biology
Giovanna Cesaro, Heloisa Tramontin da Soler, Eloise Pavao Guerra-Slompo, Ahmed Haouz, Pierre Legrand, Nilson Ivo Tonin Zanchin, Beatriz Gomes Guimaraes
Summary: Rrp44/Dis3 is a conserved eukaryotic ribonuclease that plays a role in processing and degradation of almost all types of RNA. Depletion of Rrp44 in Trypanosoma brucei blocks maturation of ribosomal RNA, leading to disruption of ribosome synthesis and inhibition of cell proliferation.
NUCLEIC ACIDS RESEARCH
(2023)
Article
Biochemical Research Methods
Claire Cargemel, Stephanie Marsin, Magali Noiray, Pierre Legrand, Halil Bounoua, Ines Li De la Sierra-Gallay, Helene Walbott, Sophie Quevillon-Cheruel
Summary: During bacterial genome replication initiation, replicative helicases rely on specialized proteins for their loading onto oriC. DnaC and DnaI were the first loaders to be characterized. However, many bacteria do not have these genes and instead have domesticated phage elements that have replaced the original loader gene dciA. A crystal structure study of the complex from Vibrio cholerae revealed that two VcDciA molecules interact with a dimer of VcDnaB without altering its canonical structure, providing insights into how DciA assists in DnaB loading. Surprisingly, DnaC from Escherichia coli also targets the same module on EcDnaB, suggesting functional interchangeability between VcDciA and EcDnaC despite their lack of structural similarity. This study represents a significant advancement in understanding the mechanism by which phage helicase loaders hijack bacterial replicative helicases during evolution.
ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Guillaume Gerbaud, Brice Barbat, Mathilde Tribout, Emilien Etienne, Valerie Belle, Badreddine Douzi, Rome Voulhoux, Alessio Bonucci
Summary: T2SS is a bacterial nanomachine consisting of an inner membrane assembly platform, an outer membrane pore, and a dynamic endopilus. This study used EPR spectroscopy to investigate the hetero-oligomeric assembly of the minor pilins in T2SS. The results support the endopilus model while also revealing conformational flexibility and alternative orientations in specific regions of the minor pilins.
Article
Biochemistry & Molecular Biology
Dariusz Czernecki, Antonin Nourisson, Pierre Legrand, Marc Delarue
Summary: Family A DNA polymerases (PolAs) are important enzymes involved in DNA replication and repair. This study re-examines all available PolA sequences and classifies them into 19 major clusters. In addition to characterizing known subfamilies, this study identifies eight new subfamilies and analyzes their general characteristics, phylogenetic relationships, and conservation in sequence motifs. The study also uses AlphaFold2 to generate prediction models for clusters lacking experimentally determined structures and identifies new features in PolAs.
NUCLEIC ACIDS RESEARCH
(2023)
Article
Multidisciplinary Sciences
Clement Madru, Markel Martinez-Carranza, Sebastien Laurent, Alessandra C. Alberti, Maelenn Chevreuil, Bertrand Raynal, Ahmed Haouz, Remy A. Le Meur, Marc Delarue, Ghislaine Henneke, Didier Flament, Mart Krupovic, Pierre Legrand, Ludovic Sauguet
Summary: Using an integrative approach, the authors characterized the structure of RPA in Archaea, revealing shared features with eukaryotes, as well as the formation of a tetrameric supercomplex in the absence of DNA. This supercomplex provides protection for ssDNA during replication. These findings contribute to our understanding of the evolution of replication factors in eukaryotes.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Ornella Bimai, Pierre Legrand, Jean-Luc Ravanat, Nadia Touati, Jingjing Zhou, Nisha He, Marine Lenon, Frederic Barras, Marc Fontecave, Beatrice Golinelli-Pimpaneau
Summary: Thiolation of uridine 34 in tRNAs is conserved in all three domains of life and is essential for accurate protein translation. The mechanism of U34-tRNA thiolation involves a [4Fe-4S] cluster, which is coordinated by conserved cysteine residues. The enzyme NcsA in archaea and the Ctu1/Ctu2 complex in eukaryotes play a crucial role in catalyzing U34-tRNA thiolation. The crystal structure of NcsA from Methanococcus maripaludis reveals the coordination of the [4Fe-4S] cluster and provides insights into the binding and activation of the sulfur donor.
SCIENTIFIC REPORTS
(2023)
Article
Microbiology
Yvann Bourigault, Charly A. Dupont, Jonas B. Desjardins, Thierry Doan, Mathilde Bouteiller, Hugo Le Guenno, Sylvie Chevalier, Corinne Barbey, Xavier Latour, Eric Cascales, Annabelle Merieau
Summary: The T6SS is a widespread nanomachine in Gram-negative bacteria, injecting effectors to protect potato tubers against pathogens. MFE01 displays aggressive behavior with continuous T6SS activity, while the secreted amidase Tae3(Pf) is toxic towards Pca and countered by the immunity protein Tai3(Pf).
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Julia Bartoli, Audrey C. Tempier, Noa L. Guzzi, Chloe M. Piras, Eric Cascales, Julie P. M. Viala
Summary: Polymorphic toxins (PTs) are a broad family of toxins involved in interbacterial competition and pathogenesis. In this study, a new family of PTs containing an N-terminal MuF domain was identified. The MuF-RelA_SpoT toxin associated with the temperate phage of Streptococcus pneumoniae SPNA45 was characterized, demonstrating its (p)ppApp synthetase activity. The study also proposed a signature for (p)ppApp synthetases and identified two immunity proteins associated with the toxin.
JOURNAL OF MOLECULAR BIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Antonia Kefala Stavridi, Amandine Gontier, Vincent Morin, Philippe Frit, Virginie Ropars, Nadia Barboule, Carine Racca, Sagun Jonchhe, Michael J. Morten, Jessica Andreani, Alexey Rak, Pierre Legrand, Alexa Bourand-Plantefol, Steven W. Hardwick, Dimitri Y. Chirgadze, Paul Davey, Taiana Maia De Oliveira, Eli Rothenberg, Sebastien Britton, Patrick Calsou, Tom L. Blundell, Paloma F. Varela, Amanda K. Chaplin, Jean-Baptiste Charbonnier
Summary: This study reveals the molecular mechanism by which the interaction between the Ku70-Ku80 heterodimer and inositol-hexaphosphate (IP6) enhances the activity of classical Non-Homologous End Joining (c-NHEJ) pathway for DNA repair.
NUCLEIC ACIDS RESEARCH
(2023)
Article
Microbiology
Solene G. Beauvois, Nicolas Flaugnatti, Marianne Ilbert, Marie Boyer, Esther Gavello-Fernandez, Remi Fronzes, Dukas Jurenas, Laure Journet
Summary: Bacteria compete for ecological niches and use T6SS to inject toxic effectors into target cells. PAAR protein plays a critical role in T6SS, interacting with VgrG protein to promote its structure formation and being necessary for T6SS baseplate assembly and sheath polymerization.
MICROBIOLOGY SPECTRUM
(2023)
Article
Chemistry, Multidisciplinary
Marie E. Perrin, Bo Li, Johanne Mbianda, May Bakail, Christophe Andre, Gwenaelle Moal, Pierre Legrand, Virginie Ropars, Celine Douat, Francoise Ochsenbein, Gilles Guichard
Summary: In this study, we investigated the substitution of 4 α-residues with 3-urea segments in a short α-helical peptide known to bind ASF1. By analyzing the effects of different foldamer replacements, we discovered new binding modes for the peptide-urea chimeras with ASF1.
CHEMICAL COMMUNICATIONS
(2023)
Article
Endocrinology & Metabolism
Carole Fruchart Gaillard, Ali Ben Djoudi Ouadda, Lidia Ciccone, Emmanuelle Girard, Sepideh Mikaeeli, Alexandra Evagelidis, Mailys Le Devehat, Delia Susan-Resiga, Evelyne Cassar Lajeunesse, Herve Nozach, Oscar Henrique Pereira Ramos, Aurelien Thureau, Pierre Legrand, Annik Prat, Vincent Dive, Nabil G. Seidah
Summary: The liver-derived circulating PCSK9 accelerates the degradation of LDL receptor in endosomes/lysosomes. Inhibition or silencing of PCSK9 is used in clinics to reduce LDL-cholesterol, thereby reducing incidence of cardiovascular disease and possibly cancer/metastasis. The mechanism by which the PCSK9-LDLR complex is sorted to degradation compartments remains unclear. This study investigates the interaction of PCSK9 with nanobody P1.40 and CAP1 to uncover their role in regulating LDLR degradation.
MOLECULAR METABOLISM
(2023)
Article
Microbiology
Boris Taillefer, Julien F. Giraud, Eric Cascales
Summary: Polymicrobial communities are influenced by interactions between different species, including the competition mediated by the type VI secretion system (T6SS). This study shows that the synthesis, assembly, contraction, and disassembly of T6SS do not result in a significant growth cost for enteroaggregative Escherichia coli.
JOURNAL OF BACTERIOLOGY
(2023)