Alípio, André FilipeBárria, CátiaPobre, VâniaMatos, Ana RitaPrata, Sara CarreraAmblar, MonicaArraiano, Cecília MariaDomingues, Susana2024-11-062024-11-062024-09-15J Mol Biol. 2024 Sep 15;436(18):168711.0022-2836https://hdl.handle.net/20.500.12105/25439The RNA-Seq data discussed in this publication have been deposited in NCBI’s Gene Expression Omnibus and are accessible through GEO Series accession number GSE262258.Previous studies on RNase R have highlighted significant effects of this ribonuclease in several processes of Streptococcus pneumoniae biology. In this work we show that elimination of RNase R results in overexpression of most of genes encoding the components of type II fatty acid biosynthesis (FASII) cluster. We demonstrate that RNase R is implicated in the turnover of most of transcripts from this pathway, affecting the outcome of the whole FASII cluster, and ultimately leading to changes in the membrane fatty acid composition. Our results show that the membrane of the deleted strain contains higher proportion of unsaturated and long-chained fatty acids than the membrane of the wild type strain. These alterations render the RNase R mutant more prone to membrane lipid peroxidation and are likely the reason for the increased sensitivity of this strain to detergent lysis and to the action of the bacteriocin nisin. Reprogramming of membrane fluidity is an adaptative cell response crucial for bacterial survival in constantly changing environmental conditions. The data presented here is suggestive of a role for RNase R in the composition of S. pneumoniae membrane, with strong impact on pneumococci adaptation to different stress situations.engVoRhttp://creativecommons.org/licenses/by-nc/4.0/FASII clusterFatty acids biosynthesisPneumococcusRibonucleaseStress resistanceBacterial ProteinsCell MembraneEndoribonucleasesFatty AcidsGene Expression Regulation, BacterialLipid PeroxidationMembrane FluidityStreptococcus pneumoniaeAttribution-NonCommercial 4.0 International390191064361816871110.1016/j.jmb.2024.1687111089-8638Journal of molecular biologyopen access