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Protein folding modulates the chemical reactivity of a Gram-positive adhesin

Gram-positive bacteria colonize mucosal tissues against large mechanical perturbations, such as coughing, which generate shear forces that exceed the ability of non-covalent bonds to remain attached. To overcome these challenges, the pathogen Streptococcus pyogenes utilizes the protein Cpa, a pilus...

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Autores principales: Alonso-Caballero, Alvaro, Echelman, Daniel J., Tapia-Rojo, Rafael, Haldar, Shubhasis, Eckels, Edward C., Fernandez, Julio M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7858226/
https://www.ncbi.nlm.nih.gov/pubmed/33257887
http://dx.doi.org/10.1038/s41557-020-00586-x
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author Alonso-Caballero, Alvaro
Echelman, Daniel J.
Tapia-Rojo, Rafael
Haldar, Shubhasis
Eckels, Edward C.
Fernandez, Julio M.
author_facet Alonso-Caballero, Alvaro
Echelman, Daniel J.
Tapia-Rojo, Rafael
Haldar, Shubhasis
Eckels, Edward C.
Fernandez, Julio M.
author_sort Alonso-Caballero, Alvaro
collection PubMed
description Gram-positive bacteria colonize mucosal tissues against large mechanical perturbations, such as coughing, which generate shear forces that exceed the ability of non-covalent bonds to remain attached. To overcome these challenges, the pathogen Streptococcus pyogenes utilizes the protein Cpa, a pilus tip-end adhesin equipped with a Cys-Gln thioester bond. The reactivity of this bond towards host surface ligands enables covalent anchoring; however, colonization also requires cell migration and spreading over surfaces. The molecular mechanisms underlying these seemingly incompatible requirements remain unknown. Here, we demonstrate a magnetic tweezers force spectroscopy assay that resolves the dynamics of Cpa thioester bond under force. While folded at forces < 6 pN, Cpa thioester bond reacts reversibly with amine ligands, that are a common occurrence in inflammation sites; however, mechanical unfolding and exposure to forces > 6 pN block thioester reformation. We hypothesize that this folding-coupled reactivity switch—“smart covalent bond”—could allow the adhesin to undergo binding and unbinding to surface ligands under low force and remain covalently attached under mechanical stress.
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spelling pubmed-78582262021-05-30 Protein folding modulates the chemical reactivity of a Gram-positive adhesin Alonso-Caballero, Alvaro Echelman, Daniel J. Tapia-Rojo, Rafael Haldar, Shubhasis Eckels, Edward C. Fernandez, Julio M. Nat Chem Article Gram-positive bacteria colonize mucosal tissues against large mechanical perturbations, such as coughing, which generate shear forces that exceed the ability of non-covalent bonds to remain attached. To overcome these challenges, the pathogen Streptococcus pyogenes utilizes the protein Cpa, a pilus tip-end adhesin equipped with a Cys-Gln thioester bond. The reactivity of this bond towards host surface ligands enables covalent anchoring; however, colonization also requires cell migration and spreading over surfaces. The molecular mechanisms underlying these seemingly incompatible requirements remain unknown. Here, we demonstrate a magnetic tweezers force spectroscopy assay that resolves the dynamics of Cpa thioester bond under force. While folded at forces < 6 pN, Cpa thioester bond reacts reversibly with amine ligands, that are a common occurrence in inflammation sites; however, mechanical unfolding and exposure to forces > 6 pN block thioester reformation. We hypothesize that this folding-coupled reactivity switch—“smart covalent bond”—could allow the adhesin to undergo binding and unbinding to surface ligands under low force and remain covalently attached under mechanical stress. 2020-11-30 2021-02 /pmc/articles/PMC7858226/ /pubmed/33257887 http://dx.doi.org/10.1038/s41557-020-00586-x Text en Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www.nature.com/authors/editorial_policies/license.html#terms
spellingShingle Article
Alonso-Caballero, Alvaro
Echelman, Daniel J.
Tapia-Rojo, Rafael
Haldar, Shubhasis
Eckels, Edward C.
Fernandez, Julio M.
Protein folding modulates the chemical reactivity of a Gram-positive adhesin
title Protein folding modulates the chemical reactivity of a Gram-positive adhesin
title_full Protein folding modulates the chemical reactivity of a Gram-positive adhesin
title_fullStr Protein folding modulates the chemical reactivity of a Gram-positive adhesin
title_full_unstemmed Protein folding modulates the chemical reactivity of a Gram-positive adhesin
title_short Protein folding modulates the chemical reactivity of a Gram-positive adhesin
title_sort protein folding modulates the chemical reactivity of a gram-positive adhesin
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7858226/
https://www.ncbi.nlm.nih.gov/pubmed/33257887
http://dx.doi.org/10.1038/s41557-020-00586-x
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