title: Loop-loop interactions involved in antisense regulation are processed by the endoribonuclease III in Staphylococcus aureus.
abstract: The endoribonuclease III (RNase III) belongs to the enzyme family known to process double-stranded RNAs. Staphylococcus aureus RNase III was shown to regulate, in concert with the quorum sensing induced RNAIII, the degradation of several mRNAs encoding virulence factors and the transcriptional repressor of toxins Rot. Two of the mRNA-RNAIII complexes involve fully base paired loop-loop interactions with similar sequences that are cleaved by RNase III at a unique position. We show here that the sequence of the base pairs within the loop-loop interaction is not critical for RNase III cleavage, but that the co-axial stacking of three consecutive helices provides an ideal topology for RNase III recognition. In contrast, RNase III induces several strong cleavages in a regular helix, which carries a sequence similar to the loop-loop interaction. The introduction of a bulged loop that interrupts the regular helix restrains the number of cleavages. This work shows that S. aureus RNase III is able to bind and cleave a variety of RNA-mRNA substrates, and that specific structure elements direct the action of RNase III.
authors.affiliation: Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, Strasbourg, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Romilly
authors.forename: Clément
authors.initials: C
authors.lastname: Chevalier
authors.forename: Stefano
authors.initials: S
authors.lastname: Marzi
authors.forename: Benoît
authors.initials: B
authors.lastname: Masquida
authors.forename: Thomas
authors.initials: T
authors.lastname: Geissmann
authors.forename: François
authors.initials: F
authors.lastname: Vandenesch
authors.forename: Eric
authors.initials: E
authors.lastname: Westhof
authors.forename: Pascale
authors.initials: P
authors.lastname: Romby
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D015964:Gene Expression Regulation, Bacterial; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D018272:Porins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D025941:Protein Interaction Mapping; D053038:Quorum Sensing; D020871:RNA Stability; D016372:RNA, Antisense / Q000235:genetics / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; C109237:OmpF protein; D018272:Porins; D016372:RNA, Antisense; D012329:RNA, Bacterial; D012333:RNA, Messenger; C096035:RNAIII, Staphylococcus aureus; D043244:Ribonuclease III
keywords: endoribonuclease; gene regulation; loop-loop interaction; processing; regulatory RNA