Studying the organization and conservation of the TonB systems across the genus Vibrio, we can tease out trends in gene arrangement and function that lead to clues about the evolution and necessity of the proteins in multiple TonB systems. The TonB2 systems, with additional TtpC proteins, are in general more promiscuous regarding their interactions with many different TonB-dependent transporters in the outer membrane. Studies show that the TtpC protein spans the periplasmic space, suggesting that it can be the connection between the energy from the proton motive force and the outer membrane protein receptors, which the shorter TonB2 cannot provide. As an earlier system, the combination of the TtpC protein and a TonB2 system must have been necessary for the function of the smaller TonB2 protein and to transduce energy in a medium that can have osmotic challenges.
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http://dx.doi.org/10.2217/fmb.10.90 | DOI Listing |
Sci Rep
December 2024
Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, 14A F. Joliot-Curie St., 50-383, Wrocław, Poland.
Iron and heme are essential nutrients for all branches of life. Pathogenic members of the Bacteroidota phylum, including Porphyromonas gingivalis, do not synthesize heme and rely on host hemoproteins for heme as a source of iron and protoporphyrin IX. P.
View Article and Find Full Text PDFMol Microbiol
December 2024
Max-Planck-Institute of Biology, Tübingen, Germany.
TonB is an essential component of an energy-generating system that powers active transport across the outer membrane (OM) of compounds that are too large or too scarce to diffuse through porins. The TonB-dependent OM transport proteins (TBDTs) consist of β barrels forming pores that are closed by plugs. The binding of TonB to TBDTs elicits plug movement, which opens the pores and enables nutrient translocation from the cell surface into the periplasm.
View Article and Find Full Text PDFPLoS Biol
December 2024
Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain.
Competitive bacteria like the human pathogen Pseudomonas aeruginosa can acquire iron from different iron carriers, which are usually internalized via outer membrane TonB-dependent receptors (TBDRs). Production of TBDRs is promoted by the presence of the substrate. This regulation often entails a signal transfer pathway known as cell-surface signaling (CSS) that involves the TBDR itself that also functions as transducer (and is thus referred to as TBDT), a cytoplasmic membrane-bound anti-σ factor, and an extracytoplasmic function σ (σECF) factor.
View Article and Find Full Text PDFJAC Antimicrob Resist
December 2024
Institute of Medical Microbiology, University of Lübeck and University Medical Center of Schleswig-Holstein, Ratzeburger Allee 160, 23562 Lübeck, Germany.
mBio
December 2024
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
Unlabelled: Acarbose is a type 2 diabetes medicine that prevents dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading , (Bo), and (Bt).
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