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Updated: Sep 19, 2025
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Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy
Published on: December 20, 2013
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Tripartite binding mode of cohesin-dockerin complexes from Ruminococcus flavefaciens involving naturally truncated
Marlene Duarte1, Ana Luísa Carvalho2, Magda C Ferreira1
1CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Lisbon, Portugal.
The Journal of Biological Chemistry
|June 4, 2025
Summary
Researchers discovered a novel tripartite binding mechanism in the R. flavefaciens cellulosome. This mechanism involves cohesin interacting with two dockerin units, enhancing polysaccharide degradation efficiency.
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- Plant cell wall polysaccharides are energy sources but hard to degrade.
- Anaerobic bacteria like R. flavefaciens use cellulosomes for efficient polysaccharide breakdown.
- Cellulosomes assemble via cohesin-dockerin interactions, but truncated dockerins' roles are unclear.
Purpose of the Study:
- To investigate the structural and binding properties of a novel cohesin-dockerin complex.
- To elucidate the function of group-2 dockerins in the R. flavefaciens cellulosome.
Main Methods:
- Structural and binding analysis of a cohesin-dockerin complex.
- Characterization of a group-2 dockerin with a truncated Ca2+-coordinating loop.
Main Results:
- A novel tripartite binding mechanism was identified.
- Cohesin can simultaneously bind two distinct dockerin units.
- Three alternative binding conformations were observed.
Conclusions:
- The findings reveal the modular versatility of the R. flavefaciens cellulosome.
- This tripartite binding enhances the efficiency of polysaccharide degradation.
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