title: Structure of the Bacillus subtilis 70S ribosome reveals the basis for species-specific stalling.
abstract: Ribosomal stalling is used to regulate gene expression and can occur in a species-specific manner. Stalling during translation of the MifM leader peptide regulates expression of the downstream membrane protein biogenesis factor YidC2 (YqjG) in Bacillus subtilis, but not in Escherichia coli. In the absence of structures of Gram-positive bacterial ribosomes, a molecular basis for species-specific stalling has remained unclear. Here we present the structure of a Gram-positive B. subtilis MifM-stalled 70S ribosome at 3.5-3.9 Å, revealing a network of interactions between MifM and the ribosomal tunnel, which stabilize a non-productive conformation of the PTC that prevents aminoacyl-tRNA accommodation and thereby induces translational arrest. Complementary genetic analyses identify a single amino acid within ribosomal protein L22 that dictates the species specificity of the stalling event. Such insights expand our understanding of how the synergism between the ribosome and the nascent chain is utilized to modulate the translatome in a species-specific manner.
authors.affiliation: Gene Center and Department for Biochemistry, University of Munich, Feodor-Lynen-Street 25, Munich 81377, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sohmen
authors.affiliation: Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Chiba
authors.affiliation: Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Shimokawa-Chiba
authors.affiliation: 1] Institut Européen de Chimie et Biologie, Université de Bordeaux, Pessac, France [2] Institut National de la Santé et de la Recherche Médicale (U869), Bordeaux, France.
authors.forename: C Axel
authors.initials: CA
authors.lastname: Innis
authors.affiliation: Gene Center and Department for Biochemistry, University of Munich, Feodor-Lynen-Street 25, Munich 81377, Germany.
authors.forename: Otto
authors.initials: O
authors.lastname: Berninghausen
authors.affiliation: 1] Gene Center and Department for Biochemistry, University of Munich, Feodor-Lynen-Street 25, Munich 81377, Germany [2] Center for integrated Protein Science Munich (CiPSM), University of Munich, Feodor-Lynen-Street 25, Munich 81377, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Beckmann
authors.affiliation: Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.
authors.forename: Koreaki
authors.initials: K
authors.lastname: Ito
authors.affiliation: 1] Gene Center and Department for Biochemistry, University of Munich, Feodor-Lynen-Street 25, Munich 81377, Germany [2] Center for integrated Protein Science Munich (CiPSM), University of Munich, Feodor-Lynen-Street 25, Munich 81377, Germany.
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Wilson
mesh_terms: D001412:Bacillus subtilis; D001426:Bacterial Proteins; D018360:Crystallography, X-Ray; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics; D008968:Molecular Conformation; D014176:Protein Biosynthesis / Q000235:genetics*; D021382:Protein Sorting Signals / Q000235:genetics; D012343:RNA, Transfer; D012269:Ribosomal Proteins; D012270:Ribosomes / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D021382:Protein Sorting Signals; D012269:Ribosomal Proteins; D012343:RNA, Transfer