Cell Reports (May 2024)

Structural and mechanistic insights into the function of Leishmania ribosome lacking a single pseudouridine modification

  • K. Shanmugha Rajan,
  • Saurav Aryal,
  • Disha-Gajanan Hiregange,
  • Anat Bashan,
  • Hava Madmoni,
  • Mika Olami,
  • Tirza Doniger,
  • Smadar Cohen-Chalamish,
  • Pascal Pescher,
  • Masato Taoka,
  • Yuko Nobe,
  • Aliza Fedorenko,
  • Tanaya Bose,
  • Ella Zimermann,
  • Eric Prina,
  • Noa Aharon-Hefetz,
  • Yitzhak Pilpel,
  • Toshiaki Isobe,
  • Ron Unger,
  • Gerald F. Späth,
  • Ada Yonath,
  • Shulamit Michaeli

Journal volume & issue
Vol. 43, no. 5
p. 114203

Abstract

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Summary: Leishmania is the causative agent of cutaneous and visceral diseases affecting millions of individuals worldwide. Pseudouridine (Ψ), the most abundant modification on rRNA, changes during the parasite life cycle. Alterations in the level of a specific Ψ in helix 69 (H69) affected ribosome function. To decipher the molecular mechanism of this phenotype, we determine the structure of ribosomes lacking the single Ψ and its parental strain at ∼2.4–3 Å resolution using cryo-EM. Our findings demonstrate the significance of a single Ψ on H69 to its structure and the importance for its interactions with helix 44 and specific tRNAs. Our study suggests that rRNA modification affects translation of mRNAs carrying codon bias due to selective accommodation of tRNAs by the ribosome. Based on the high-resolution structures, we propose a mechanism explaining how the ribosome selects specific tRNAs.

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