title: A regulatory role for Staphylococcus aureus toxin-antitoxin system PemIKSa.
abstract: Toxin-antitoxin systems were shown to be involved in plasmid maintenance when they were initially discovered, but other roles have been demonstrated since. Here we identify and characterize a novel toxin-antitoxin system (pemIKSa) located on Staphylococcus aureus plasmid pCH91. The toxin (PemKSa) is a sequence-specific endoribonuclease recognizing the tetrad sequence U↓AUU, and the antitoxin (PemISa) inhibits toxin activity by physical interaction. Although the toxin-antitoxin system is responsible for stable plasmid maintenance our data suggest the participation of pemIKSa in global regulation of staphylococcal virulence by alteration of the translation of large pools of genes. We propose a common mechanism of reversible activation of toxin-antitoxin systems based on antitoxin transcript resistance to toxin cleavage. Elucidation of this mechanism is particularly interesting because reversible activation is a prerequisite for the proposed general regulatory role of toxin-antitoxin systems.
authors.affiliation: Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Bukowski
authors.forename: Robert
authors.initials: R
authors.lastname: Lyzen
authors.forename: Weronika M
authors.initials: WM
authors.lastname: Helbin
authors.forename: Emilia
authors.initials: E
authors.lastname: Bonar
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szalewska-Palasz
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wegrzyn
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Dubin
authors.forename: Adam
authors.initials: A
authors.lastname: Dubin
authors.forename: Benedykt
authors.initials: B
authors.lastname: Wladyka
mesh_terms: D000992:Antitoxins / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006706:Homeostasis; D008954:Models, Biological; D010957:Plasmids / Q000378:metabolism; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D013211:Staphylococcus aureus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014118:Toxins, Biological / Q000378:metabolism*; D059467:Transcriptome / Q000235:genetics
chemical_list: D000992:Antitoxins; D012333:RNA, Messenger; D014118:Toxins, Biological; D012260:Ribonucleases