title: Bacteriophage P22 ejects all of its internal proteins before its genome.
abstract: Double-stranded DNA bacteriophages are highly pressurized, providing a force driving ejection of a significant fraction of the genome from its capsid. In P22-like Podoviridae, internal proteins ("E proteins") are packaged into the capsid along with the genome, and without them the virus is not infectious. However, little is known about how and when these proteins come out of the virus. We employed an in vitro osmotic suppression system with high-molecular-weight polyethylene glycol to study P22 E protein release. While slow ejection of the DNA can be triggered by lipopolysaccharide (LPS), the rate is significantly enhanced by the membrane protein OmpA from Salmonella. In contrast, E proteins are not ejected unless both OmpA and LPS are present and their ejection when OmpA is present is largely complete before any genome is ejected, suggesting that E proteins play a key role in the early stage of transferring P22 DNA into the host.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Michigan State University, Department of Biochemistry and Molecular Biology, East Lansing, MI 48824, USA.
authors.forename: Sophia M
authors.initials: SM
authors.lastname: Sdao
authors.affiliation: Michigan State University, Department of Biochemistry and Molecular Biology, East Lansing, MI 48824, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Dover
authors.affiliation: Michigan State University, Department of Biochemistry and Molecular Biology, East Lansing, MI 48824, USA; Michigan State University, Department of Microbiology and Molecular Genetics, East Lansing, MI 48824, USA.
authors.forename: Natalia B
authors.initials: NB
authors.lastname: Porcek
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Knobler
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA. Electronic address: gelbart@chem.ucla.edu.
authors.forename: William M
authors.initials: WM
authors.lastname: Gelbart
authors.affiliation: Michigan State University, Department of Biochemistry and Molecular Biology, East Lansing, MI 48824, USA. Electronic address: kparent@msu.edu.
authors.forename: Kristin N
authors.initials: KN
authors.lastname: Parent
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000302:isolation & purification / Q000494:pharmacology; D017100:Bacteriophage P22 / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D001696:Biomechanical Phenomena; D002213:Capsid / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure; D004279:DNA, Viral / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016679:Genome, Viral; D008070:Lipopolysaccharides / Q000494:pharmacology; D009995:Osmosis; D011092:Polyethylene Glycols / Q000737:chemistry; D012486:Salmonella typhimurium / Q000737:chemistry / Q000821:virology; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D053586:Virus Internalization / Q000187:drug effects
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004279:DNA, Viral; D008070:Lipopolysaccharides; D014764:Viral Proteins; C078167:OMPA outer membrane proteins; D011092:Polyethylene Glycols
keywords: Bacteriophage infectivity; Genome ejection; Internal protein ejection; Osmotic suppression; Receptors