title: Genome characterization of lipid-containing marine bacteriophage PM2 by transposon insertion mutagenesis.
abstract: Bacteriophage PM2 presently is the only member of the Corticoviridae family. The virion consists of a protein-rich lipid vesicle, which is surrounded by an icosahedral protein capsid. The lipid vesicle encloses a supercoiled circular double-stranded DNA genome of 10,079 bp. PM2 belongs to the marine phage community and is known to infect two gram-negative Pseudoalteromonas species. In this study, we present a characterization of the PM2 genome made using the in vitro transposon insertion mutagenesis approach. Analysis of 101 insertion mutants yielded information on the essential and dispensable regions of the PM2 genome and led to the identification of several new genes. A number of lysis-deficient mutants as well as mutants displaying delayed- and/or incomplete-lysis phenotypes were identified. This enabled us to identify novel lysis-associated genes with no resemblance to those previously described from other bacteriophage systems. Nonessential genome regions are discussed in the context of PM2 genome evolution.
authors.affiliation: Department of Biological and Environmental Sciences, Institute of Biotechnology, Viikki Biocenter 2, P.O. Box 56 (Viikinkaari 5), FIN-00014 University of Helsinki, Finland.
authors.forename: Mart
authors.initials: M
authors.lastname: Krupovic
authors.forename: Heikki
authors.initials: H
authors.lastname: Vilen
authors.forename: Jaana K H
authors.initials: JK
authors.lastname: Bamford
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Kivelä
authors.forename: Juha-Matti
authors.initials: JM
authors.lastname: Aalto
authors.forename: Harri
authors.initials: H
authors.lastname: Savilahti
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Bamford
mesh_terms: D000595:Amino Acid Sequence; D019240:Corticoviridae / Q000235:genetics*; D004247:DNA / Q000235:genetics; D004251:DNA Transposable Elements; D019143:Evolution, Molecular; D016678:Genome; D016679:Genome, Viral; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016366:Open Reading Frames; D010641:Phenotype; D031161:Pseudoalteromonas
chemical_list: D004251:DNA Transposable Elements; D008055:Lipids; D004247:DNA