title: Analysis of r-protein and RNA conformation of 30S subunit intermediates in bacteria.
abstract: The ribosome is a large macromolecular complex that must be assembled efficiently and accurately for the viability of all organisms. In bacteria, this process must be robust and tunable to support life in diverse conditions from the ice of arctic glaciers to thermal hot springs. Assembly of the Small ribosomal SUbunit (SSU) of Escherichia coli has been extensively studied and is highly temperature-dependent. However, a lack of data on SSU assembly for other bacteria is problematic given the importance of the ribosome in bacterial physiology. To broaden the understanding of how optimal growth temperature may affect SSU assembly, in vitro SSU assembly of two thermophilic bacteria, Geobacillus kaustophilus and Thermus thermophilus, was compared with that of E. coli. Using these phylogenetically, morphologically, and environmentally diverse bacteria, we show that SSU assembly is highly temperature-dependent and efficient SSU assembly occurs at different temperatures for each organism. Surprisingly, the assembly landscape is characterized by at least two distinct intermediate populations in the organisms tested. This novel, second intermediate, is formed in the presence of the full complement of r-proteins, unlike the previously observed RI* particle formed in the absence of late-binding r-proteins in E. coli. This work reveals multiple distinct intermediate populations are present during SSU assembly in vitro for several bacteria, yielding insights into RNP formation and possible antimicrobial development toward this common SSU target.
authors.affiliation: Department of Biology, University of Rochester, Rochester, New York 14627, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Napper
authors.affiliation: Department of Biology, University of Rochester, Rochester, New York 14627, USA Center for RNA Biology: from Genome to Therapeutics, University of Rochester Medical Center, Rochester, New York 14627, USA.
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Culver
mesh_terms: D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry*; D056506:Geobacillus / Q000235:genetics; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D012329:RNA, Bacterial / Q000737:chemistry*; D054679:Ribosome Subunits, Small / Q000737:chemistry; D013696:Temperature; D016963:Thermus thermophilus / Q000737:chemistry
chemical_list: D029968:Escherichia coli Proteins; D012329:RNA, Bacterial
keywords: E. coli; G. kaustophilus; T. thermophilus; in vitro assembly; ribosome; small subunit