The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range
ABSTRACT The bacterial pathogen Staphylococcus pseudintermedius is involved in canine otitis externa and pyoderma as well as in surgical wound and urinary tract infections. Invasion of canine epithelial cells is promoted by S. pseudintermedius fibronectin (Fn)-binding proteins SpsD and SpsL through...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2020-08-01
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| Series: | mBio |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/mBio.00371-20 |
| _version_ | 1818990209561264128 |
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| author | Felipe Viela Marion Mathelié-Guinlet Giampiero Pietrocola Pietro Speziale Yves F. Dufrêne |
| author_facet | Felipe Viela Marion Mathelié-Guinlet Giampiero Pietrocola Pietro Speziale Yves F. Dufrêne |
| author_sort | Felipe Viela |
| collection | DOAJ |
| description | ABSTRACT The bacterial pathogen Staphylococcus pseudintermedius is involved in canine otitis externa and pyoderma as well as in surgical wound and urinary tract infections. Invasion of canine epithelial cells is promoted by S. pseudintermedius fibronectin (Fn)-binding proteins SpsD and SpsL through molecular interactions that are currently unknown. By means of single-molecule experiments, we discover that both adhesins have distinct molecular mechanisms for binding to Fn. We show that the SpsD-Fn interaction has a strength equivalent to that of a covalent bond (∼1.5 to 1.8 nN), which is an order of magnitude stronger than the binding force of classical receptor-ligand complexes. We suggest that this extreme mechanostability originates from the β-sheet organization of a tandem β-zipper. Upon binding to FnI modules, the intrinsically disordered binding sequences of SpsD would shift into an ordered structure by forming additional β-strands along triple peptide β-sheets in the Fn molecule. Dynamic force measurements reveal an unexpected behavior, i.e., that strong bonds are activated by mechanical tension as observed with catch bonds. By contrast, the SpsL-Fn interaction involves multiple weak bonds (∼0.2 nN) that rupture sequentially under force. Together with the recently described dock, lock, and latch complex, the ultrastrong interaction unraveled here is among the strongest noncovalent biological interaction measured to date. Our findings may find applications for the identification of inhibitory compounds to treat infections triggered by pathogens engaged in tandem β-zipper interactions. IMPORTANCE Binding of Staphylococcus pseudintermedius surface proteins SpsD and SpsL to fibronectin (Fn) plays a critical role in the invasion of canine epithelial cells. Here, we discover that both adhesins have different mechanisms for binding to Fn. The force required to separate SpsD from Fn is extremely strong, consistent with the unusual β-sheet organization of a high-affinity tandem β-zipper. By contrast, unbinding of the SpsL-Fn complex involves the sequential rupture of single weak bonds. Our findings may be of biological relevance as SpsD and SpsL are likely to play complementary roles during invasion. While the SpsD β-zipper supports strong bacterial adhesion and triggers invasion, the weak SpsL interaction would favor fast detachment, enabling the pathogen to colonize new sites. |
| first_indexed | 2024-12-20T19:50:44Z |
| format | Article |
| id | doaj.art-6cd3c3ad82c14ad5a2c9cf0194120098 |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-12-20T19:50:44Z |
| publishDate | 2020-08-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-6cd3c3ad82c14ad5a2c9cf01941200982022-12-21T19:28:19ZengAmerican Society for MicrobiologymBio2150-75112020-08-0111410.1128/mBio.00371-20The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton RangeFelipe Viela0Marion Mathelié-Guinlet1Giampiero Pietrocola2Pietro Speziale3Yves F. Dufrêne4Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, BelgiumLouvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, BelgiumDepartment of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, ItalyDepartment of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, ItalyLouvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, BelgiumABSTRACT The bacterial pathogen Staphylococcus pseudintermedius is involved in canine otitis externa and pyoderma as well as in surgical wound and urinary tract infections. Invasion of canine epithelial cells is promoted by S. pseudintermedius fibronectin (Fn)-binding proteins SpsD and SpsL through molecular interactions that are currently unknown. By means of single-molecule experiments, we discover that both adhesins have distinct molecular mechanisms for binding to Fn. We show that the SpsD-Fn interaction has a strength equivalent to that of a covalent bond (∼1.5 to 1.8 nN), which is an order of magnitude stronger than the binding force of classical receptor-ligand complexes. We suggest that this extreme mechanostability originates from the β-sheet organization of a tandem β-zipper. Upon binding to FnI modules, the intrinsically disordered binding sequences of SpsD would shift into an ordered structure by forming additional β-strands along triple peptide β-sheets in the Fn molecule. Dynamic force measurements reveal an unexpected behavior, i.e., that strong bonds are activated by mechanical tension as observed with catch bonds. By contrast, the SpsL-Fn interaction involves multiple weak bonds (∼0.2 nN) that rupture sequentially under force. Together with the recently described dock, lock, and latch complex, the ultrastrong interaction unraveled here is among the strongest noncovalent biological interaction measured to date. Our findings may find applications for the identification of inhibitory compounds to treat infections triggered by pathogens engaged in tandem β-zipper interactions. IMPORTANCE Binding of Staphylococcus pseudintermedius surface proteins SpsD and SpsL to fibronectin (Fn) plays a critical role in the invasion of canine epithelial cells. Here, we discover that both adhesins have different mechanisms for binding to Fn. The force required to separate SpsD from Fn is extremely strong, consistent with the unusual β-sheet organization of a high-affinity tandem β-zipper. By contrast, unbinding of the SpsL-Fn complex involves the sequential rupture of single weak bonds. Our findings may be of biological relevance as SpsD and SpsL are likely to play complementary roles during invasion. While the SpsD β-zipper supports strong bacterial adhesion and triggers invasion, the weak SpsL interaction would favor fast detachment, enabling the pathogen to colonize new sites.https://journals.asm.org/doi/10.1128/mBio.00371-20single moleculemechanostabilitybinding forcestaphylococcal adhesionSpsDfibronectin |
| spellingShingle | Felipe Viela Marion Mathelié-Guinlet Giampiero Pietrocola Pietro Speziale Yves F. Dufrêne The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range mBio single molecule mechanostability binding force staphylococcal adhesion SpsD fibronectin |
| title | The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range |
| title_full | The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range |
| title_fullStr | The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range |
| title_full_unstemmed | The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range |
| title_short | The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range |
| title_sort | molecular complex between staphylococcal adhesin spsd and fibronectin sustains mechanical forces in the nanonewton range |
| topic | single molecule mechanostability binding force staphylococcal adhesion SpsD fibronectin |
| url | https://journals.asm.org/doi/10.1128/mBio.00371-20 |
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