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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...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
2020
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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. |
format | Online Article Text |
id | pubmed-7858226 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
record_format | MEDLINE/PubMed |
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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