Roles of Lipopolysaccharide and the Outer Membrane Protein OmpC on Bacteriophage T4 Infectivity in Escherichia coli

Abstract

Although previous studies have demonstrated that lipopolysaccharide (LPS) and the outer membrane protein OmpC are required for bacteriophage T4 infectivity in Escherichia coli, it is unclear whether they played a role in binding or in the downstream viral processes that followed. Such processes may vary from phage DNA injection to viral gene expression, assembly, or release. To investigate this further, phage binding and overlay plaque assays were performed on E. coli strains C149 (wildtype), C845 (LPS mutant), C842 (LPS mutant), and C157 (OmpC mutant). In this study, we report that LPS and OmpC play an essential role in one or more viral processes that follow binding. In addition, it was discovered that LPS and OmpC mutants C842 and C157, respectively, did not alter phage binding affinity but decreased phage binding stability. Moreover, the LPS mutant, C845, increased binding affinity to T4 phage but decreased binding stability. All these results suggest that modifications to LPS can influence both the affinities and stabilities of phage binding.