{"entity": "publication", "iuid": "1c57a97c200a453f883feb3a6b0e660d", "timestamp": "2026-07-17T04:58:06.557Z", "links": {"self": {"href": "https://publications.scilifelab.se/publication/1c57a97c200a453f883feb3a6b0e660d.json"}, "display": {"href": "https://publications.scilifelab.se/publication/1c57a97c200a453f883feb3a6b0e660d"}}, "title": "Numerous rRNA molecules form the apicomplexan mitoribosome via repurposed protein and RNA elements.", "authors": [{"family": "Shikha", "given": "Shikha", "initials": "S", "orcid": "0000-0002-7878-1463", "researcher": {"href": "https://publications.scilifelab.se/researcher/2de6231587194596b907dddf06be1b45.json"}}, {"family": "Tobiasson", "given": "Victor", "initials": "V", "orcid": "0000-0001-8920-017X", "researcher": {"href": "https://publications.scilifelab.se/researcher/5208789057a94d0d9575476bf9c88d5a.json"}}, {"family": "Ferreira Silva", "given": "Mariana", "initials": "M"}, {"family": "Ovciarikova", "given": "Jana", "initials": "J"}, {"family": "Beraldi", "given": "Dario", "initials": "D", "orcid": "0000-0003-1504-5212", "researcher": {"href": "https://publications.scilifelab.se/researcher/2912e8a492a04a1aa8e3dab72e1ed37c.json"}}, {"family": "M\u00fchleip", "given": "Alexander", "initials": "A", "orcid": "0000-0002-1877-2282", "researcher": {"href": "https://publications.scilifelab.se/researcher/921b5acb5b7c402fa06c8c148cbd5340.json"}}, {"family": "Sheiner", "given": "Lilach", "initials": "L", "orcid": "0000-0001-5909-2307", "researcher": {"href": "https://publications.scilifelab.se/researcher/8e426f417f194a75ae9fbc76ea24040e.json"}}], "type": "journal article", "published": "2025-01-18", "journal": {"title": "Nat Commun", "issn": "2041-1723", "volume": "16", "issue": "1", "pages": "817", "issn-l": "2041-1723"}, "abstract": "Mitochondrial ribosomes (mitoribosomes) are essential, and their function of synthesising mitochondrial proteins is universal. The core of almost all mitoribosomes is formed from a small number of long and self-folding rRNA molecules. In contrast, the mitoribosome of the apicomplexan parasite Toxoplasma gondii assembles from over 50 extremely short rRNA molecules. Here, we use cryo-EM to discover the features that enable this unusual mitoribosome to perform its function. We reveal that poly-A tails added to rRNA molecules are integrated into the ribosome, and we demonstrate their essentiality for mitoribosome formation and for parasite survival. This is a distinct function for poly-A tails, which are otherwise known primarily as stabilisers of messenger RNAs. Furthermore, while ribosomes typically consist of unique rRNA sequences, here nine sequences are used twice, each copy integrated in a different mitoribosome domain, revealing one of the mechanisms enabling the extreme mitochondrial genome reduction characteristic to Apicomplexa and to a large group of related microbial eukaryotes. Finally, several transcription factor-like proteins are repurposed to compensate for reduced or lost critical ribosomal domains, including members of the ApiAP2 family thus far considered to be DNA-binding transcription factors.", "doi": "10.1038/s41467-025-56057-9", "pmid": "39827269", "labels": {"Cryo-EM": "Service"}, "xrefs": [{"db": "pmc", "key": "PMC11742926"}, {"db": "pii", "key": "10.1038/s41467-025-56057-9"}], "notes": [], "created": "2025-11-13T09:43:13.776Z", "modified": "2025-11-13T09:43:13.956Z"}