title: A pathogenicity island replicon in Staphylococcus aureus replicates as an unstable plasmid.
abstract: The SaPIs are 14- to 17-kb mobile pathogenicity islands in staphylococci that carry genes for superantigen toxins and other virulence factors and are responsible for the toxic shock syndrome and other superantigen-related diseases. They reside at specific chromosomal sites and are induced by certain bacteriophages to initiate an excision-replication-packaging program, resulting in their incorporation into small infective phage-like particles. These are responsible for very high transfer frequencies that often equal and sometimes exceed the plaque-forming titer of the inducing phage. The ability of the SaPIs to replicate autonomously defines them as individual replicons and, like other prokaryotic replicons, they possess replicon-specific initiation functions. In this paper, we report identification of the SaPI replication origin (ori) and replication initiation protein (Rep), which has helicase as well as initiation activity. The SaPI oris are binding sites for the respective Rep proteins and consist of multiple oligonucleotide repeats in two sets, flanking an AT-rich region that may be the site of initial melting. Plasmids containing the rep-ori complex plus an additional gene, pri, can replicate autonomously in Staphylococcus aureus but are very unstable, probably because of defective segregation.
authors: Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, Department of Microbiology, New York, NY 10016, USA.
authors: Carles
authors: C
authors: Ubeda
authors: Peter
authors: P
authors: Barry
authors: José R
authors: JR
authors: Penadés
authors: Richard P
authors: RP
authors: Novick
mesh_terms: D004265:DNA Helicases / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics / Q000378:metabolism; D044404:Genomic Islands / Q000235:genetics*; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics*; D011485:Protein Binding; D012093:Replicon / Q000235:genetics*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000472:pathogenicity
chemical_list: C100902:endodeoxyribonuclease SapI; D015252:Deoxyribonucleases, Type II Site-Specific; D004265:DNA Helicases
references: Mol Microbiol. 2007 Jul;65(1):41-50
references: 17581119
references: Appl Environ Microbiol. 2004 Oct;70(10):6076-85
references: 15466553
references: J Bacteriol. 2007 Aug;189(15):5608-16
references: 17545290
references: Mol Microbiol. 2001 Jul;41(2):365-77
references: 11489124
references: Bacteriol Rev. 1969 Jun;33(2):210-63
references: 4896350
references: J Bacteriol. 1995 Aug;177(15):4333-41
references: 7635818
references: Gene. 1992 Dec 1;122(1):187-92
references: 1452028
references: Mol Microbiol. 1998 Jul;29(2):527-43
references: 9720870
references: J Biochem. 1994 Jun;115(6):1113-8
references: 7982891
references: J Bacteriol. 2005 Nov;187(21):7292-308
references: 16237012
references: Microbiol Rev. 1993 Sep;57(3):683-702
references: 8246844
references: Mol Microbiol. 2003 Jul;49(1):193-210
references: 12823821
references: Plasmid. 2003 Sep;50(2):95-101
references: 12932735
references: J Mol Biol. 1986 Oct 5;191(3):367-82
references: 2950236
references: Mol Microbiol. 2005 May;56(3):836-44
references: 15819636
references: EMBO J. 1991 Sep;10(9):2707-15
references: 1651234
references: Mol Gen Genet. 1993 Oct;241(1-2):185-92
references: 8232203
references: Nucleic Acids Res. 2003 Dec 1;31(23):6828-40
references: 14627816
references: Chem Immunol Allergy. 2007;93:42-57
references: 17369699
references: Proc Natl Acad Sci U S A. 2005 Sep 13;102(37):13272-7
references: 16135568
references: J Cell Sci Suppl. 1987;7:15-31
references: 3332651
references: Plasmid. 1979 Apr;2(2):207-15
references: 451049
references: J Bacteriol. 2001 Jan;183(1):63-70
references: 11114901