title: RNase Y is responsible for uncoupling the expression of translation factor IF3 from that of the ribosomal proteins L35 and L20 in Bacillus subtilis.
abstract: RNase Y is a novel endoribonuclease affecting global mRNA metabolism. We show that this nuclease affects the expression of the Bacillus subtilis infC-rpmI-rplT operon, encoding translation initiation factor IF3 and the ribosomal proteins L35 and L20. This operon is autoregulated by a complex L20-dependent transcription attenuation mechanism. L20 binds to a phylogenetically conserved domain on the 5' untranslated region of the infC mRNA which mimics the L20 binding sites on 23S rRNA. We have identified a second promoter (P1) upstream of the previously identified promoter (P2). The P1, but not the P2, readthrough transcript is stabilized in a strain depleted for RNase Y. However, under these conditions infC biosynthesis is repressed threefold. We show that the unprocessed P1 transcript is non-functional for IF3 translation but fully competent to express the co-transcribed ribosomal protein genes. RNase Y cleavage of the P1 transcript creates an entry site for the 5'-3' exonucleolytic activity of RNase J1 which degrades the infC mRNA when translation initiation efficiency is low. A second RNase Y cleavage is crucial for initiating degradation of the prematurely terminated infC leader RNAs, including the L20 operator complex, which permits efficient recycling of the L20 protein.
authors.affiliation: CNRS UPR 9073, Univ Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
authors.forename: Patrice
authors.initials: P
authors.lastname: Bruscella
authors.forename: Karen
authors.initials: K
authors.lastname: Shahbabian
authors.forename: Soumaya
authors.initials: S
authors.lastname: Laalami
authors.forename: Harald
authors.initials: H
authors.lastname: Putzer
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D008954:Models, Biological; D008969:Molecular Sequence Data; D039665:Prokaryotic Initiation Factor-3 / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D020871:RNA Stability; D012260:Ribonucleases / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000096:biosynthesis*
chemical_list: D039665:Prokaryotic Initiation Factor-3; D012269:Ribosomal Proteins; D012260:Ribonucleases