title: Sequence determinants for DNA packaging specificity in the S. aureus pathogenicity island SaPI1.
abstract: The SaPIs and their relatives are a family of genomic islands that exploit helper phages for high frequency horizontal transfer. One of the mechanisms used by SaPIs to accomplish this molecular piracy is the redirection of the helper phage DNA packaging machinery. SaPIs encode a small terminase subunit that can be substituted for that of the phage. In this study we have determined the initial packaging cleavage sites for helper phage 80α, which uses the phage-encoded small terminase subunit, and for SaPI1, which uses the SaPI-encoded small terminase subunit. We have identified a 19nt SaPI1 sequence that is necessary and sufficient to allow high frequency 80α transduction of a plasmid by a terminase carrying the SaPI1-encoded small subunit. We also show that the hybrid enzyme with the SaPI1 small terminase subunit is capable of generalized transduction.
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, PO Box 980678, Richmond, VA 23298-0678, USA; Centre of Biological Engineering, IBB - Institute for Biotechnology and Bioengineering, University of Minho, Campus de Gualtar 4710-057, Braga, Portugal. Electronic address: jcbento@vcu.edu.
authors.forename: Joana C
authors.initials: JC
authors.lastname: Bento
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, PO Box 980678, Richmond, VA 23298-0678, USA. Electronic address: lanekd@vcu.edu.
authors.forename: Kristin D
authors.initials: KD
authors.lastname: Lane
authors.affiliation: Division of Monoclonal Antibodies, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA. Electronic address: Erik.Read@fda.hhs.gov.
authors.forename: Erik K
authors.initials: EK
authors.lastname: Read
authors.affiliation: Centre of Biological Engineering, IBB - Institute for Biotechnology and Bioengineering, University of Minho, Campus de Gualtar 4710-057, Braga, Portugal. Electronic address: nunocerca@ceb.uminho.pt.
authors.forename: Nuno
authors.initials: N
authors.lastname: Cerca
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, PO Box 980678, Richmond, VA 23298-0678, USA. Electronic address: christie@vcu.edu.
authors.forename: Gail E
authors.initials: GE
authors.lastname: Christie
mesh_terms: D002874:Chromosome Mapping; D042003:DNA Packaging; D004269:DNA, Bacterial / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D044404:Genomic Islands; D010957:Plasmids; D017422:Sequence Analysis, DNA; D013204:Staphylococcus Phages / Q000235:genetics*; D013211:Staphylococcus aureus / Q000235:genetics*; D014161:Transduction, Genetic
chemical_list: D004269:DNA, Bacterial; D004279:DNA, Viral; D004706:Endodeoxyribonucleases; C030894:terminase
keywords: DNA packaging; Helper phage; Pac site; Pathogenicity island; SaPI; Terminase