Biophysical Society Thematic Meeting | Ascona 2026

Mechanobiology of Infection

Monday Speaker Abstracts

FLEXIBLE MOTION OF T7 BACTERIOPHAGE TAIL FIBERS SUGGEST A DYNAMIC VIRAL INFECTION MECHANISM Luca Elizabet Kosik 1,4 ; Miklós Cervenak 1 ; Dominik Sziklai 1 ; Andrea Balogh-Molnár 1 ; Negar Rahimi 1,5 ; Bence Fehér 1,5 ; Soma Yamamoto 2 ; Hiroki Konno 2 ; Noriyuki Kodera 2 ; Holger Flechsig 2 ; Romain Amyot 2 ; Heinz Amenitsch 3 ; Hedvig Tordai 1 ; Levente Herényi 1 ; Miklós Kellermayer 1,4 ; Balint Kiss 1,4 ; 1 Semmelweis University, Biophysics and Radiation Biology, Budapest, Hungary 2 Kanazawa University, NanoLSI, Kanazawa, Japan Viruses are nanoscale infectious agents capable of specifically targeting and reprograming host cells. A unique group of viruses, bacteriophages, have regained popularity in research partly due to the rising number of multidrug-resistant bacterial infections. Phages could potentially replace antibiotics, but only if we understand every detail of their structure and infection cycle. T7 bacteriophages are a group of dsDNA viruses, which infect E. coli bacteria by recognizing their surface lipopolysaccharides (LPS). T7 virions are comprised of an icosahedral protein shell which encapsulates the genomic DNA, and a tail-fiber complex which is primarily used for target recognition and DNA injection. The virus has six” L”-shaped, ~40 nm long fibers (gp17 protein trimers) attached to the tail-tube, which are thought to be essential for initial host recognition and possibly surface exploration. Using high-speed atomic force microscopy (HS AFM) we observed the molecular structure and movements of isolated tail fibers and the dynamics of fiber to LPS binding. Firstly, we have identified a hinge region within the fibers, which makes them highly flexible, allowing the bending of their distal region. Furthermore, we have observed the dynamic triple helical coiled coil structure of the proximal region, which would allow fiber rotation. These two points of flexibility allow a more efficient and highly dynamic host recognition and virus anchoring process. The observed flexibility might allow host surface exploration by walking. Such flexibility in the host recognition machinery may not be unique to T7 bacteriophages, getting us one step closer to understanding the intricate details of virus-host interactions. 3 Graz University of Technology, Inorganic Chemistry, Graz, Austria 4 HUN-REN-SE, Biophysical Virology Group, Budapest, Hungary 5 HUN-REN, Nanobiophysics Research Group, Budapest, Hungary

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