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Discovery and structural characterization of the D-box, a conserved TonB motif that couples an inner-membrane motor to outer-membrane transport.
Loll, Patrick J; Grasty, Kimberly C; Shultis, David D; Guzman, Nicholas J; Wiener, Michael C.
Afiliação
  • Loll PJ; Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA. Electronic address: pjl28@drexel.edu.
  • Grasty KC; Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
  • Shultis DD; Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
  • Guzman NJ; Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
  • Wiener MC; Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA. Electronic address: michael.wiener@ttuhsc.edu.
J Biol Chem ; 300(3): 105723, 2024 Mar.
Article em En | MEDLINE | ID: mdl-38311172
ABSTRACT
Gram-negative bacteria use TonB-dependent transport to take up nutrients from the external environment, employing the Ton complex to import a variety of nutrients that are either scarce or too large to cross the outer membrane unaided. The Ton complex contains an inner-membrane motor (ExbBD) that generates force, as well as nutrient-specific transport proteins on the outer membrane. These two components are coupled by TonB, which transmits the force from the inner to the outer membrane. TonB contains an N-terminus anchored in the inner membrane, a C-terminal domain that binds the outer-membrane transporter, and a proline-rich linker connecting the two. While much is known about the interaction between TonB and outer-membrane transporters, the critical interface between TonB and ExbBD is less well understood. Here, we identify a conserved motif within TonB that we term the D-box, which serves as an attachment point for ExbD. We characterize the interaction between ExbD and the D-box both functionally and structurally, showing that a homodimer of ExbD captures one copy of the D-box peptide via beta-strand recruitment. We additionally show that both the D-box motif and ExbD are conserved in a range of Gram-negative bacteria, including members of the ESKAPE group of pathogens. The ExbDD-box interaction is likely to represent an important aspect of force transduction between the inner and outer membranes. Given that TonB-dependent transport is an important contributor to virulence, this interaction is an intriguing potential target for novel antibacterial therapies.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Proteínas de Bactérias / Proteínas de Membrana Idioma: En Revista: J Biol Chem Ano de publicação: 2024 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Proteínas de Bactérias / Proteínas de Membrana Idioma: En Revista: J Biol Chem Ano de publicação: 2024 Tipo de documento: Article