1. Genome-Wide Analysis of Antigen 43 (Ag43) Variants: New Insights in Their Diversity, Distribution and Prevalence in Bacteria
- Author
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Valentin Ageorges, Ivan Wawrzyniak, Philippe Ruiz, Cédric Bicep, Mohamed A. Zorgani, Jason J. Paxman, Begoña Heras, Ian R. Henderson, Sabine Leroy, Xavier Bailly, Panagiotis Sapountzis, Eric Peyretaillade, Mickaël Desvaux, Microbiologie Environnement Digestif Santé (MEDIS), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA), Laboratoire Microorganismes : Génome et Environnement (LMGE), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), La Trobe University, The University of Queensland, FIM2Lab – Functional Interfacial Materials and Membrane Laboratory, School of Chemical Engineering, Brisbane, QLD 4067, Australia (FIM2Lab), University of Queensland [Brisbane], Unité Mixte de Recherche d'Épidémiologie des maladies Animales et zoonotiques (UMR EPIA), and VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
- Subjects
Inorganic Chemistry ,[SDV]Life Sciences [q-bio] ,Organic Chemistry ,Escherichia coli ,protein secretion ,autotransporter ,Type V protein secretion system (T5SS) ,phylogeny ,gene diversity ,bacterial pathogens ,cell surface protein ,aggregation ,bacterial colonisation and infection and infection ,General Medicine ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy ,Catalysis ,Uncategorized ,Computer Science Applications - Abstract
Antigen 43 (Ag43) expression induces aggregation and biofilm formation that has consequences for bacterial colonisation and infection. Ag43 is secreted through the Type 5 subtype “a” secretion system (T5aSS) and is a prototypical member of the family of self-associating autotransporters (SAATs). As a T5aSS protein, Ag43 has a modular architecture comprised of (i) a signal peptide, (ii) a passenger domain that can be subdivided into three subdomains (SL, EJ, and BL), (iii) an autochaperone (AC) domain, and (iv) an outer membrane translocator. The cell-surface SL subdomain is directly involved in the “Velcro-handshake” mechanism resulting in bacterial autoaggregation. Ag43 is considered to have a ubiquitous distribution in E. coli genomes and many strains harbour multiple agn43 genes. However, recent phylogenetic analyses indicated the existence of four distinct Ag43 classes exhibiting different propensities for autoaggregation and interactions. Given the knowledge of the diversity and distribution of Ag43 in E. coli genomes is incomplete, we have performed a thorough in silico investigation across bacterial genomes. Our comprehensive analyses indicate that Ag43 passenger domains cluster in six phylogenetic classes associated with different SL subdomains. The diversity of Ag43 passenger domains is a result of the association of the SL subtypes with two different EJ-BL-AC modules. We reveal that agn43 is almost exclusively present among bacterial species of the Enterobacteriaceae family and essentially in the Escherichia genus (99.6%) but that it is not ubiquitous in E. coli. The gene is typically present as a single copy but up to five copies of agn43 with different combinations of classes can be observed. The presence of agn43 as well as its different classes appeared to differ between Escherichia phylogroups. Strikingly, agn43 is present in 90% of E. coli from E phylogroup. Our results shed light on Ag43 diversity and provide a rational framework for investigating its role in E. coli ecophysiology and physiopathology.
- Published
- 2023
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