title: Identification and characterization of the single-stranded DNA-binding protein of bacteriophage P1.
abstract: The genome of bacteriophage P1 harbors a gene coding for a 162-amino-acid protein which shows 66% amino acid sequence identity to the Escherichia coli single-stranded DNA-binding protein (SSB). The expression of the P1 gene is tightly regulated by P1 immunity proteins. It is completely repressed during lysogenic growth and only weakly expressed during lytic growth, as assayed by an ssb-P1/lacZ fusion construct. When cloned on an intermediate-copy-number plasmid, the P1 gene is able to suppress the temperature-sensitive defect of an E. coli ssb mutant, indicating that the two proteins are functionally interchangeable. Many bacteriophages and conjugative plasmids do not rely on the SSB protein provided by their host organism but code for their own SSB proteins. However, the close relationship between SSB-P1 and the SSB protein of the P1 host, E. coli, raises questions about the functional significance of the phage protein.
authors.affiliation: Institute of Molecular Biology, University of Southern Denmark, Main Campus Odense University, DK-5230 Odense M, Denmark. lehnherr@biobase.dk
authors.forename: H
authors.initials: H
authors.lastname: Lehnherr
authors.forename: J D
authors.initials: JD
authors.lastname: Bendtsen
authors.forename: F
authors.initials: F
authors.lastname: Preuss
authors.forename: T V
authors.initials: TV
authors.lastname: Ilyina
mesh_terms: D000595:Amino Acid Sequence; D001433:Bacteriolysis; D017101:Bacteriophage P1 / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D017124:Conserved Sequence; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000821:virology; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D014764:Viral Proteins