Assembly and substrate recognition of curli biogenesis system

Area of Science:

• Microbiology
• Structural Biology
• Biochemistry

Background:

• Bacterial biofilms, major contributors to infections, rely on curli amyloid fibrils.
• The curli biogenesis system is crucial for secreting these amyloid structures.
• Understanding curli biogenesis is key to developing anti-biofilm therapies.

Purpose of the Study:

• To systematically investigate the curli biogenesis system.
• To elucidate the structure, function, and assembly of the CsgF-CsgG secretion complex.
• To identify mechanisms for inhibiting curli secretion and formation.

Main Methods:

• Structural, biochemical, and functional analyses of the CsgF-CsgG secretion channel complex.
• Investigation of complex assembly with curli components (CsgA, CsgB) and CsgE.
• Analysis of curli-cell association mediated by CsgF.

Main Results:

• The CsgF-CsgG complex exhibits a dual-pore architecture.
• A strategy to inhibit curli secretion by physically reducing the CsgF pore size was developed.
• Specific recognition sites for the CsgA substrate (N-terminus) on the CsgG channel were identified.

Conclusions:

• The study provides comprehensive insights into the curli biogenesis mechanism.
• Structural and functional characterization of the CsgF-CsgG complex offers therapeutic targets.
• Understanding curli substrate recognition by CsgG is crucial for controlling biofilm formation.