title: Conserved GTPase LepA (Elongation Factor 4) functions in biogenesis of the 30S subunit of the 70S ribosome.
abstract: The physiological role of LepA, a paralog of EF-G found in all bacteria, has been a mystery for decades. Here, we show that LepA functions in ribosome biogenesis. In cells lacking LepA, immature 30S particles accumulate. Four proteins are specifically underrepresented in these particles-S3, S10, S14, and S21-all of which bind late in the assembly process and contribute to the folding of the 3' domain of 16S rRNA. Processing of 16S rRNA is also delayed in the mutant strain, as indicated by increased levels of precursor 17S rRNA in assembly intermediates. Mutation ΔlepA confers a synthetic growth phenotype in absence of RsgA, another GTPase, well known to act in 30S subunit assembly. Analysis of the ΔrsgA strain reveals accumulation of intermediates that resemble those seen in the absence of LepA. These data suggest that RsgA and LepA play partially redundant roles to ensure efficient 30S assembly.
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH 43210.|Center for RNA Biology, The Ohio State University, Columbus, OH 43210.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Gibbs
authors.affiliation: Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
authors.forename: Kyung-Mee
authors.initials: KM
authors.lastname: Moon
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH 43210.|Center for RNA Biology, The Ohio State University, Columbus, OH 43210.|Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210.
authors.forename: Menglin
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH 43210.|Center for RNA Biology, The Ohio State University, Columbus, OH 43210.|Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210.
authors.forename: Rohan
authors.initials: R
authors.lastname: Balakrishnan
authors.affiliation: Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
authors.forename: Leonard J
authors.identifier: 0000-0001-8551-4817
authors.initials: LJ
authors.lastname: Foster
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH 43210; fredrick.5@osu.edu.|Center for RNA Biology, The Ohio State University, Columbus, OH 43210.|Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210.
authors.forename: Kurt
authors.initials: K
authors.lastname: Fredrick
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D020558:GTP Phosphohydrolases / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D008958:Models, Molecular; D001678:Organelle Biogenesis; D010448:Peptide Initiation Factors / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D011487:Protein Conformation; D012322:RNA Precursors / Q000378:metabolism; D012329:RNA, Bacterial / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D054680:Ribosome Subunits, Small, Bacterial / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C515651:LepA protein, E coli; D010448:Peptide Initiation Factors; D012322:RNA Precursors; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; D020558:GTP Phosphohydrolases; C467318:RsgA protein, E coli
keywords: EF4; RsgA; YjeQ; protein synthesis; translation