Loop-loop interactions involved in antisense regulation are processed by the endoribonuclease III in Staphylococcus aureus.
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.
['Romilly|Cédric|C|', 'Chevalier|Clément|C|', 'Marzi|Stefano|S|', 'Masquida|Benoît|B|', 'Geissmann|Thomas|T|', 'Vandenesch|François|F|', 'Westhof|Eric|E|', 'Romby|Pascale|P|']
D001426:Bacterial Proteins D004789:Enzyme Activation D015964:Gene Expression Regulation, Bacterial D008958:Models, Molecular D016297:Mutagenesis, Site-Directed D009690:Nucleic Acid Conformation D018272:Porins D011485:Protein Binding D014176:Protein Biosynthesis D025941:Protein Interaction Mapping D053038:Quorum Sensing D020871:RNA Stability D016372:RNA, Antisense D012329:RNA, Bacterial D012333:RNA, Messenger D043244:Ribonuclease III D013211:Staphylococcus aureus D013329:Structure-Activity Relationship
loop-loop interaction processing endoribonuclease gene regulation regulatory RNA