Using cryogenic electron microscopy methods to gain insight into structure and initial host attachment of the flagellotropic bacteriophage 7-7-1

bioRxiv (Cold Spring Harbor Laboratory)

Abstract

Abstract Understanding the structural and functional mechanisms of bacteriophage 7-7-1, the flagellotropic phage infecting Agrobacterium sp. H13-3, offers promising insights into phage-host interactions. Using single particle analysis (SPA) cryo-electron microscopy (cryo-EM), we determined the capsid and tail structure, and built atomic models of capsid hexamers, pentamers and tail. Combined with cryo-electron tomography (cryo-ET) and machine learning methodologies, our findings indicate that phage 7-7-1 uses capsid fibers to establish initial contact with the host flagellum, followed by subsequent attachment to cell surface receptors. Proteinase K treatment confirmed the time-dependent degradation of capsid fibers. The study also demonstrated that capsid fibers are flexible and can interact with other phages and host flagella, suggesting a cooperative infection strategy. These results provide crucial structural insights and may open avenues for developing phage-based therapeutics against resistant bacterial pathogens.

Authors 8

1. Willem E. M. Noteborn Aachen Netherlands Centre for Electron Nanoscopy (NeCEN)

   Leiden University

   Affiliation as printed

   Netherlands Centre for Electron Nanoscopy, Leiden University, Einsteinweg 55, 2333CC Leiden, The Netherlands

   Netherlands Centre for Electron Nanoscopy, Leiden University

2. Ruochen Ouyang Aachen Institute of Biology, Leiden University

   Leiden University · Chinese Academy of Sciences · Institute of Software

   Affiliation as printed

   Institute of Biology, Leiden University, Sylviusweg 72, 2333BE Leiden, The Netherlands

   Laboratory of Intelligence Engineering, Institute of Software Chinese Academy of Science, Zhongguancun South Forth Road 4, Beijing, 100090, China

   Institute of Software Chinese Academy of Science

3. T. Hoeksma Aachen Institute of Biology, Leiden University

   Leiden University

   Affiliation as printed

   Institute of Biology, Leiden University, Sylviusweg 72, 2333BE Leiden, The Netherlands

   Institute of Biology, Leiden University

4. Adam Sidi Mabrouk Aachen Institute of Biology, Leiden University

   Leiden University

   Affiliation as printed

   Institute of Biology, Leiden University, Sylviusweg 72, 2333BE Leiden, The Netherlands

   Institute of Biology, Leiden University

5. Nathaniel C. Esteves

   Virginia Tech

   Affiliation as printed

   Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA

   Virginia Polytechnic Institute and State University

6. Daniël M. Pelt Aachen Leiden Institute of Advanced Computer Science

   Leiden University

   Affiliation as printed

   Leiden Institute of Advanced Computer Science, Leiden University, Niels Bohrweg 1, 2333CA Leiden, The Netherlands

   Leiden Institute of Advanced Computer Science, Leiden University

7. Birgit E. Scharf

   Virginia Tech

   Affiliation as printed

   Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA

   Virginia Polytechnic Institute and State University

8. Ariane Briegel corresponding Aachen Institute of Biology, Leiden University

   Leiden University · Centre National de la Recherche Scientifique · Institut Pasteur · Biologie Moléculaire Structurale et Processus Infectieux

   Affiliation as printed

   Institute of Biology, Leiden University, Sylviusweg 72, 2333BE Leiden, The Netherlands

   Integrative Structural Cell Biology Unit, Department of Structural Biology and Chemistry, CNRS UMR 3528, Institut Pasteur, 75724 Paris, France

   Institut Pasteur