title: Key residues of S. flexneri OmpA mediate infection by bacteriophage Sf6.
abstract: Many viruses, including bacteriophage, have the inherent ability to utilize several types of proteinaceous receptors as an attachment mechanism to infect cells, yet the molecular mechanisms that drive receptor binding have not been elucidated. Using bacteriophage Sf6 and its host, Shigella flexneri, we investigated how Sf6 utilizes outer membrane protein A (OmpA) for infection. Specifically, we identified that surface loops of OmpA mediate Shigella infection. We further characterized which residues in the surface loops are responsible for Sf6 binding and productive infection using a combination of in vivo and in vitro approaches including site-directed mutagenesis, phage plaque assays, circular dichroism spectroscopy, and in vitro genome ejection assays. Our data indicate that Sf6 can productively interact with other bacterial OmpAs as long as they share homology in loops 2 and 4, suggesting that these loops may determine host specificity. Our data provide a model in which Sf6 interacts with OmpA using the surface of the protein and new insights into viral attachment through binding to membrane protein receptors.
authors: Michigan State University Department of Microbiology and Molecular Genetics, East Lansing, MI 48824, USA; Michigan State University Department of Biochemistry and Molecular Biology, East Lansing, MI 48824, USA.
authors: Natalia B
authors: NB
authors: Porcek
authors: Michigan State University Department of Biochemistry and Molecular Biology, East Lansing, MI 48824, USA.
authors: Kristin N
authors: KN
authors: Parent
mesh_terms: D019943:Amino Acid Substitution; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001435:Bacteriophages / Q000235:genetics / Q000254:growth & development*; D002942:Circular Dichroism; D004279:DNA, Viral / Q000235:genetics; D016679:Genome, Viral; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics*; D012763:Shigella flexneri / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D014771:Virion / Q000502:physiology*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004279:DNA, Viral; C078167:OMPA outer membrane proteins
keywords: circular dichroism; outer membrane proteins; phage attachment; plaque assay; virus receptor