Biophysical Society Thematic Meeting | Ascona 2026

Mechanobiology of Infection

Poster Abstracts

27-POS Board 27 LPS - T7 BACTERIOPHAGE RBD INTERACTIONS: A MOLECULAR DYNAMICS STUDY Dominik Sziklai 1 ; Bálint Kiss 1,2 ; Bence Fehér 1,3 ; 1 Semmelweis University, Department of Biophysics and Radiation Biology, Budapest, Hungary 2 Semmelweis University, HUN-REN-SE Biophysical Virology Group, Budapest, Hungary 3 HUN-REN Office for Supported Research Groups, Nanobiophysics Research Group, Budapest, Hungary Bacteriophage T7 infects Escherichia coli and remains a key model for phage biology and engineering. Despite its broad use, the molecular basis by which the T7 tail fiber homotrimer (gp17) anchors to the E. coli outer membrane is not fully resolved. EM results only provide summation images of the global fiber geometries. Here, we characterize receptor-binding domain (RBD) interactions with lipopolysaccharide (LPS) at atomistic resolution using all-atom molecular dynamics and steered molecular dynamics (SMD) with multiple replicas. The gp17 RBD is brought into contact with LPS bilayers of defined composition to identify preferred binding geometries and interfacial interaction networks. After equilibration of the bound complex, we apply controlled separation along the membrane normal to probe adhesion strength and to pinpoint LPS moieties and gp17 residues that dominate resistance to dissociation. The simulations indicate composition-dependent binding, with specific LPS chemotypes forming larger contact areas and more persistent interaction motifs.

81