@article{1cb6749f836e4ca986c2b5ac9136610e,
title = "Cryo-EM structure of the highly atypical cytoplasmic ribosome of Euglena gracilis",
abstract = "Ribosomal RNA is the central component of the ribosome, mediating its functional and architectural properties. Here, we report the cryo-EM structure of a highly divergent cytoplasmic ribosome from the single-celled eukaryotic alga Euglena gracilis. The Euglena large ribosomal subunit is distinct in that it contains 14 discrete rRNA fragments that are assembled non-covalently into the canonical ribosome structure. The rRNA is substantially enriched in post-transcriptional modifications that are spread far beyond the catalytic RNA core, contributing to the stabilization of this highly fragmented ribosome species. A unique cluster of five adenosine base methylations is found in an expansion segment adjacent to the protein exit tunnel, such that it is positioned for interaction with the nascent peptide. As well as featuring distinctive rRNA expansion segments, the Euglena ribosome contains four novel ribosomal proteins, localized to the ribosome surface, three of which do not have orthologs in other eukaryotes.",
author = "Donna Matzov and Masato Taoka and Yuko Nobe and Yoshio Yamauchi and Yehuda Halfon and Nofar Asis and Ella Zimermann and Haim Rozenberg and Anat Bashan and Shashi Bhushan and Toshiaki Isobe and Gray, {Michael W.} and Ada Yonath and Moran Shalev-Benami",
note = "We thank Dr R.M.R. Gawryluk for providing a clustered Euglena gracilis transcriptome, Dr D.F. Spencer for database support and Dr M.N. Schnare for helpful advice and comment. We particularly wish to recognize Dr Schnare's careful and comprehensive work over several decades on the Euglena cytoribosome, which stimulated and underpinned the study reported here. We also thank Dr Moshe Peretz, Shoshana Tel-Or and Dr Maggie Kessler for experimental support. Funding - ERC-PoC [862028 to A.Y.]; Weizmann-Krenter-Katz Interdisciplinary Research (to M.S.-B.); M.S.-B. is supported by the Zuckerman STEM Leadership Program; Ilse Katz Institute for Material Sciences and Magnetic Resonance Research; Helen & Milton A. Kimmelman Center for Biomolecular Structure & Assembly; Joseph and Wolf Lebovic Lab; Dov and Ziva Rabinovich Endowed Fund for Structural Biology; Harmstieg New Scientist Fund; Pearl Welinsky Merlo Foundation; Paul and Tina Gardner; M.W.G. acknowledges past research support in this area from the Natural Sciences and Engineering Research Council of Canada [NSERC A8387]; Canadian Institutes of Health Research [CIHR MOP-11212]; D.M. is supported by the Clore Fellowship; T.I. acknowledges the support from the Japan Science and Technology Agency for Core Research for Evolutional Science and Technology [13415564]. Author contributions: M.S.-B. designed and coordinated the experiments; M.S.-B. purified the ribosomes with the help of N.A., S.B. and Y.H. prepared cryo-grids and acquired the cryo-EM data. D.M. processed the cryo-EM data and built the atomic model with the help of E.Z., A.B., H.R. and M.S.-B. M.W.G. inferred protein sequences from transcriptome data. M.T., Y.N., Y.Y. and T.I. executed MS experiments and performed protein and RNA MS analysis. D.M., M.S.-B. and M.W.G interpreted results. M.S.-B., D.M., M.W.G. and A.Y. wrote the manuscript with input from A.B. M.S.-B., M.W.G., T.I. and A.Y. supervised the project.",
year = "2020",
month = nov,
day = "18",
doi = "https://doi.org/10.1093/nar/gkaa893",
language = "الإنجليزيّة",
volume = "48",
pages = "11750--11761",
journal = "Nucleic acids research",
issn = "0305-1048",
publisher = "Oxford University Press",
number = "20",
}