Ruiz de los Mozos Aliaga, IgorVergara Irigaray, MartaSegura, VíctorVillanueva San Martín, MaiteBitarte Manzanal, NereaSaramago, MargaridaDomingues, SusanaArraiano, Cecilia M.Fechter, PierreRomby, PascaleValle Turrillas, JaioneSolano Goñi, CristinaLasa Uzcudun, ÍñigoToledo Arana, Alejandro2015-12-222015-12-2220131553-7390 (Print)1553-7404 (Electronic)10.1371/journal.pgen.1004001https://academica-e.unavarra.es/handle/2454/19768UPNa. Instituto de Agrobiotecnología. Laboratorio de Biofilms Microbianos.Incluye 10 ficheros de datosThe presence of regulatory sequences in the 39 untranslated region (39-UTR) of eukaryotic mRNAs controlling RNA stability and translation efficiency is widely recognized. In contrast, the relevance of 39-UTRs in bacterial mRNA functionality has been disregarded. Here, we report evidences showing that around one-third of the mapped mRNAs of the major human pathogen Staphylococcus aureus carry 39-UTRs longer than 100-nt and thus, potential regulatory functions. We selected the long 39-UTR of icaR, which codes for the repressor of the main exopolysaccharidic compound of the S. aureus biofilm matrix, to evaluate the role that 39-UTRs may play in controlling mRNA expression. We showed that base pairing between the 39- UTR and the Shine-Dalgarno (SD) region of icaR mRNA interferes with the translation initiation complex and generates a double-stranded substrate for RNase III. Deletion or substitution of the motif (UCCCCUG) within icaR 39-UTR was sufficient to abolish this interaction and resulted in the accumulation of IcaR repressor and inhibition of biofilm development. Our findings provide a singular example of a new potential post-transcriptional regulatory mechanism to modulate bacterial gene expression through the interaction of a 39-UTR with the 59-UTR of the same mRNA.application/pdfeng© 2013 Ruiz de los Mozos et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Base pairing interactionStaphylococcus aureusmRNA expression5-UTR3-UTRicaRArtículo / ArtikuluaAcceso abierto / Sarbide irekiainfo:eu-repo/semantics/openAccess