Base Pairing Interaction between 5′- and 3′-UTRs Controls icaR mRNA Translation in Staphylococcus aureus
(A) In vitro RNase III activity assay. A 32P-labelled 5′-UTR fragment was incubated with purified recombinant S. aureus RNase III during different times in the absence or presence of either the 3′-UTR fragment or the substituted 3′-UTR fragment. The two RNA bands that are generated by the presence of the wild type 3′-UTR are indicated with arrows. (B) Schematic representation showing in vivo mRACE results. Mapping of icaR mRNA fragments naturally generated in vivo was carried out with circularized RNAs and two outward primers (RT and PCR) that pair next to the transcriptional terminator. Black and white triangles indicate in vivo processing sites identified in the icaR mRNA wild type and the icaR mRNA with the UCCCC substitution respectively.