Structural studies of RNase M5 reveal two-metal-ion supported two-step dsRNA cleavage for 5S rRNA maturation.
Fiche publication
Date publication
février 2021
Journal
RNA biology
Auteurs
Membres identifiés du Cancéropôle Est :
Dr CIANFERANI Sarah
Tous les auteurs :
Oerum S, Catala M, Bourguet M, Gilet L, Barraud P, Cianférani S, Condon C, Tisné C
Lien Pubmed
Résumé
All species transcribe ribosomal RNA in an immature form that requires several enzymes for processing into mature rRNA. The number and types of enzymes utilised for these processes vary greatly between different species. In low G+C Gram-positive bacteria including and , the endoribonuclease (RNase) M5 performs the final step in 5S rRNA maturation, by removing the 3'- and 5'-extensions from precursor (pre) 5S rRNA. This cleavage activity requires initial complex formation between the pre-rRNA and a ribosomal protein, uL18, making the full M5 substrate a ribonucleoprotein particle (RNP). M5 contains a catalytic N-terminal Toprim domain and an RNA-binding C-terminal domain, respectively shown to assist in processing and binding of the RNP. Here, we present structural data that show how two Mg ions are accommodated in the active site pocket of the catalytic Toprim domain and investigate the importance of these ions for catalysis. We further perform solution studies that support the previously proposed 3'-before-5' order of removal of the pre-5S rRNA extensions and map the corresponding M5 structural rearrangements during catalysis.
Mots clés
(up to ten): Ribosomal RNA, 5S, M5, Toprim domain, maturation, mechanism, processing, ribonuclease
Référence
RNA Biol. 2021 Feb 4;: