Functional amyloid proteins confer defence against predatory bacteria

• 成果类型: Article
• 署名作者: Ledvina, Hannah E.; Sayegh, Ryan; Carale, Ricardo O.; Burroughs, A. Maxwell; Macklin, Alexa R.; Azadeh, Ashley L.; Najera, Layla D. Borja; Aravind, L.; Whiteley, Aaron T.
• 署名单位: University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder; National Institutes of Health (NIH) - USA; Division of Intramural Research (DIR); NIH National Library of Medicine (NLM)
• 刊物名称: Nature
• ISSN/ISSBN: 0028-1509
• DOI: 10.1038/s41586-025-09204-7
• 发表日期: 2025-08-07
• 关键词: complete genome sequence; mariner-based transposon; escherichia-coli; biofilm formation; bdellovibrio-bacteriovorus; surface organelles; curli biogenesis; sigma-factor; expression; mutagenesis

摘要

Bdellovibrio bacteriovorus is a predatory bacterium that non-selectively preys on Gram-negative bacteria by invading the prey-cell periplasm, leaching host nutrients and ultimately lysing the infected cell to exit and find a new host1,2. The predatory life cycle of B. bacteriovorus is, in many ways, comparable to a bacteriophage. However, unlike phage defence, defence against B. bacteriovorus has not been widely investigated. Here we screened a collection of diverse Escherichia coli strains for resistance to B. bacteriovorus and identified that roughly one-third of strains robustly defended against predation by producing curli fibres. Curli fibres are oligomers of the functional amyloid protein CsgA, which is exceptionally durable3. Using genetics and microscopy, we demonstrate that curli fibres provide a barrier that protects susceptible cells independent of genes required for biofilm formation. This barrier further protected E. coli against attack by the predatory bacterium Myxococcus xanthus and select phages. Bioinformatic analysis of bacterial amyloids showed these systems are diverse and widespread in diderm bacteria (those with both inner and outer membranes). One of these, an evolutionarily distinct amyloid encoded by Pseudomonas aeruginosa, also protected against B. bacteriovorus. This work establishes that functional amyloids defend bacteria against a wide range of threats.