title: Symportin 1 chaperones 5S RNP assembly during ribosome biogenesis by occupying an essential rRNA-binding site.
abstract: During 60S biogenesis, mature 5S RNP consisting of 5S RNA, RpL5 and RpL11, assembles into a pre-60S particle, where docking relies on RpL11 interacting with helix 84 (H84) of the 25S RNA. How 5S RNP is assembled for recruitment into the pre-60S is not known. Here we report the crystal structure of a ternary symportin Syo1-RpL5-N-RpL11 complex and provide biochemical and structural insights into 5S RNP assembly. Syo1 guards the 25S RNA-binding surface on RpL11 and competes with H84 for binding. Pull-down experiments show that H84 releases RpL11 from the ternary complex, but not in the presence of 5S RNA. Crosslinking mass spectrometry visualizes structural rearrangements on incorporation of 5S RNA into the Syo1-RpL5-RpL11 complex supporting the formation of a pre-5S RNP. Our data underline the dual role of Syo1 in ribosomal protein transport and as an assembly platform for 5S RNP.
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Fabiola R
authors: FR
authors: Calviño
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Satyavati
authors: S
authors: Kharde
authors: European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
authors: Alessandro
authors: http://orcid.org/0000-0002-3046-0871
authors: A
authors: Ori
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Astrid
authors: A
authors: Hendricks
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Klemens
authors: K
authors: Wild
authors: Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland.
authors: Dieter
authors: D
authors: Kressler
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Gert
authors: G
authors: Bange
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Ed
authors: E
authors: Hurt
authors: European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
authors: Martin
authors: http://orcid.org/0000-0002-7397-1321
authors: M
authors: Beck
authors: Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
authors: Irmgard
authors: I
authors: Sinning
mesh_terms: D000818:Animals; D001665:Binding Sites; D002597:Chaetomium; D018360:Crystallography, X-Ray; D004331:Drosophila melanogaster; D004926:Escherichia coli; D006801:Humans; D013058:Mass Spectrometry; D018832:Molecular Chaperones; D001678:Organelle Biogenesis; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae
chemical_list: C586434:HEATR3 protein, human; D018832:Molecular Chaperones; D011506:Proteins; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; C027624:ribosomal protein L11