ジャーナル: Science / 年: 2024 タイトル: Mechanism of bacterial predation via ixotrophy. 著者: Yun-Wei Lien / Davide Amendola / Kang Soo Lee / Nina Bartlau / Jingwei Xu / Go Furusawa / Martin F Polz / Roman Stocker / Gregor L Weiss / Martin Pilhofer / 要旨: Ixotrophy is a contact-dependent predatory strategy of filamentous bacteria in aquatic environments for which the molecular mechanism remains unknown. We show that predator-prey contact can be ...Ixotrophy is a contact-dependent predatory strategy of filamentous bacteria in aquatic environments for which the molecular mechanism remains unknown. We show that predator-prey contact can be established by gliding motility or extracellular assemblages we call "grappling hooks." Cryo-electron microscopy identified the grappling hooks as heptamers of a type IX secretion system substrate. After close predator-prey contact is established, cryo-electron tomography and functional assays showed that puncturing by a type VI secretion system mediated killing. Single-cell analyses with stable isotope-labeled prey revealed that prey components are taken up by the attacker. Depending on nutrient availability, insertion sequence elements toggle the activity of ixotrophy. A marine metagenomic time series shows coupled dynamics of ixotrophic bacteria and prey. We found that the mechanism of ixotrophy involves multiple cellular machineries, is conserved, and may shape microbial populations in the environment.
A: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1 B: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1 C: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1 D: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1 E: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1 F: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1 G: The grappling hook protein A in the bacterium Aureispira sp. CCB-QB1