Quasi-essentiality of RNase Y in<i>Bacillus subtilis</i>is caused by its critical role in the control of mRNA homeostasis

Abstract RNA turnover is essential in all domains of life. The endonuclease RNase Y (rny) one the key components involved metabolism model organism Bacillus subtilis. Essentiality has been a matter discussion, since deletion rny gene possible, but leads to severe phenotypic effects. In this work, we demonstrate that mutant strain rapidly evolves suppressor mutations at least partially alleviate these defects. All mutants had acquired duplication an about 60 kb long genomic region encompassing genes for three core subunits polymerase—α, β, β′. When polymerase was prevented by relocation rpoA B. subtilis genome, carried distinct single point evolutionary conserved regions coding either β or β’ were not tolerated wild type bacteria. vitro transcription assays with mutated variants showed decrease efficiency. Altogether, our results suggest tight cooperation between and establish optimal homeostasis cells.