title: 60S ribosome biogenesis requires rotation of the 5S ribonucleoprotein particle.
abstract: During eukaryotic ribosome biogenesis, nascent ribosomal RNA (rRNA) forms pre-ribosomal particles containing ribosomal proteins and assembly factors. Subsequently, these immature rRNAs are processed and remodelled. Little is known about the premature assembly states of rRNAs and their structural rearrangement during ribosome biogenesis. Using cryo-EM we characterize a pre-60S particle, where the 5S rRNA and its associated ribosomal proteins L18 and L5 (5S ribonucleoprotein (RNP)) are rotated by almost 180° when compared with the mature subunit. Consequently, neighbouring 25S rRNA helices that protrude from the base of the central protuberance are deformed. This altered topology is stabilized by nearby assembly factors (Rsa4 and Nog1), which were identified by fitting their three-dimensional structures into the cryo-EM density. We suggest that the 5S RNP performs a semicircular movement during 60S biogenesis to adopt its final position, fulfilling a chaperone-like function in guiding the flanking 25S rRNA helices of the central protuberance to their final topology.
authors.affiliation: Gene Center and Center of Integrated Protein Science Munich (CiPS-M), Department of Chemistry and Biochemistry, University of Munich, 81377 Munich, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Leidig
authors.affiliation: Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Thoms
authors.affiliation: Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Holdermann
authors.affiliation: Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Bradatsch
authors.affiliation: Gene Center and Center of Integrated Protein Science Munich (CiPS-M), Department of Chemistry and Biochemistry, University of Munich, 81377 Munich, Germany.
authors.forename: Otto
authors.initials: O
authors.lastname: Berninghausen
authors.affiliation: 1] Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany [2].
authors.forename: Gert
authors.initials: G
authors.lastname: Bange
authors.affiliation: Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany.
authors.forename: Irmgard
authors.initials: I
authors.lastname: Sinning
authors.affiliation: Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany.
authors.forename: Ed
authors.initials: E
authors.lastname: Hurt
authors.affiliation: Gene Center and Center of Integrated Protein Science Munich (CiPS-M), Department of Chemistry and Biochemistry, University of Munich, 81377 Munich, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Beckmann
mesh_terms: D053898:Biosynthetic Pathways / Q000502:physiology*; D015153:Blotting, Western; D019295:Computational Biology; D020285:Cryoelectron Microscopy; D003460:Crystallization; D019204:GTP-Binding Proteins / Q000378:metabolism; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000378:metabolism; D011487:Protein Conformation; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D054683:Ribosome Subunits, Large, Eukaryotic / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D012270:Ribosomes / Q000502:physiology*; D012399:Rotation; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: C475027:NOG1 protein, S cerevisiae; D009687:Nuclear Proteins; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; C504806:Rsa4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins