PT  - JOURNAL ARTICLE
AU  - Heddy Soufari
AU  - Florent Waltz
AU  - Camila Parrot
AU  - Stéphanie Durrieu
AU  - Anthony Bochler
AU  - Lauriane Kuhn
AU  - Marie Sissler
AU  - Yaser Hashem
TI  - Structure of the full kinetoplastids mitoribosome and insight on its large subunit maturation
AID  - 10.1101/2020.05.02.073890
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.05.02.073890
4099  - http://biorxiv.org/content/early/2020/05/03/2020.05.02.073890.short
4100  - http://biorxiv.org/content/early/2020/05/03/2020.05.02.073890.full
AB  - Kinetoplastids are unicellular eukaryotic parasites responsible for human pathologies such as Chagas disease, sleeping sickness or Leishmaniasis (1). They possess a single large mitochondrion, essential for the parasite survival (2). In kinetoplastids mitochondrion, most of the molecular machineries and gene expression processes have significantly diverged and specialized, with an extreme example being their mitochondrial ribosomes(3). These large complexes are in charge of translating the few essential mRNAs encoded by mitochondrial genomes (4, 5). Structural studies performed in Trypanosoma brucei already highlighted the numerous peculiarities of these mitoribosomes and the maturation of their small subunit (3, 6). However, several important aspects mainly related to the large subunit remain elusive, such as the structure and maturation of its ribosomal RNA (3). Here, we present a cryo-electron microscopy study of the protozoans Leishmania tarentolae and Trypanosoma cruzi mitoribosomes. For both species, we obtained the structure of their mature mitoribosomes, complete rRNA of the large subunit as well as previously unidentified ribosomal proteins. Most importantly, we introduce the structure of an LSU assembly intermediate in presence of 16 identified maturation factors. These maturation factors act both on the intersubunit and solvent sides of the LSU, where they refold and chemically modify the rRNA and prevent early translation before full maturation of the LSU.Competing Interest StatementThe authors have declared no competing interest.