staphylococcus aureus rnaiii binds to two distant regions of coa mrna to arrest translation and promote mrna degradation金黄色葡萄球菌rnaiii辅酶a mrna结合两个遥远地区逮捕翻译,促进信使rna降解.pdf

Staphylococcus aureus RNAIII Binds to Two Distant Regions of coa mRNA to Arrest Translation and Promote mRNA Degradation ´ 1 2 ´ 1 1 1 Clement Chevalier , Sandrine Boisset , Cedric Romilly , Benoit Masquida , Pierre Fechter , Thomas 2 2 1 Geissmann , Franc¸ois Vandenesch *, Pascale Romby * ´ ´ ´ ´ ´ 1 Architecture et Reactivite de l’ARN, Universite de Strasbourg, CNRS, IBMC, Strasbourg, France, 2 INSERM U851, Centre National de Reference des Staphylocoques, Lyon, ´ France; Universite de Lyon, Lyon, France Abstract Staphylococcus aureus RNAIII is the intracellular effector of the quorum sensing system that temporally controls a large number of virulence factors including exoproteins and cell-wall-associated proteins. Staphylocoagulase is one major virulence factor, which promotes clotting of human plasma. Like the major cell surface protein A, the expression of staphylocoagulase is strongly repressed by the quorum sensing system at the post-exponential growth phase. Here we used a combination of approaches in vivo and in vitro to analyze the mechanism used by RNAIII to regulate the expression of staphylocoagulase. Our data show that RNAIII represses the synthesis of the protein through a direct binding with the mRNA. Structure mapping shows that two distant regions of RNAIII interact with coa mRNA and that the mRNA harbors a conserved signature as found in other RNAIII-target mRNAs. The resulting complex is composed of an imperfect duplex masking the