Non-canonical Staphylococcus aureus pathogenicity island repression. Issue 19 (6th October 2022)

• Record Type: Journal Article
• Authors: Miguel-Romero, Laura; Alqasmi, Mohammed; Bacarizo, Julio; Tan, Jason A; Cogdell, Richard J; Chen, John; Byron, Olwyn; Christie, Gail E; Marina, Alberto; Penadés, José R
• Is Part Of: Nucleic acids research. Volume 50:Issue 19(2022)
• Page Start: 11109
• Page End: 11127
• Publication Date: 2022-10-06
• Subjects: Nucleic acids -- Periodicals; Molecular biology -- Periodicals; 572.805
• DOI: 10.1093/nar/gkac855
• Languages: English
• ISSNs: 0305-1048

Abstract

Abstract: Mobile genetic elements control their life cycles by the expression of a master repressor, whose function must be disabled to allow the spread of these elements in nature. Here, we describe an unprecedented repression-derepression mechanism involved in the transfer of Staphylococcus aureus pathogenicity islands (SaPIs). Contrary to the classical phage and SaPI repressors, which are dimers, the SaPI1 repressor Stl SaPI1 presents a unique tetrameric conformation never seen before. Importantly, not just one but two tetramers are required for SaPI1 repression, which increases the novelty of the system. To derepress SaPI1, the phage-encoded protein Sri binds to and induces a conformational change in the DNA binding domains of Stl SaPI1, preventing the binding of the repressor to its cognate Stl SaPI1 sites. Finally, our findings demonstrate that this system is not exclusive to SaPI1 but widespread in nature. Overall, our results characterize a novel repression-induction system involved in the transfer of MGE-encoded virulence factors in nature.