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Publication Abstract from PubMed

The pathways for ribosomal RNA (rRNA) maturation diverge greatly among the domains of life. In the Gram-positive model bacterium, Bacillus subtilis, the final maturation steps of the two large ribosomal subunit (50S) rRNAs, 23S and 5S pre-rRNAs, are catalyzed by the double-strand specific ribonucleases (RNases) Mini-RNase III and RNase M5, respectively. Here we present a protocol that allowed us to solve the 3.0 and 3.1 A resolution cryoelectron microscopy structures of these RNases poised to cleave their pre-rRNA substrates within the B. subtilis 50S particle. These data provide the first structural insights into rRNA maturation in bacteria by revealing how these RNases recognize and process double-stranded pre-rRNA. Our structures further uncover how specific ribosomal proteins act as chaperones to correctly fold the pre-rRNA substrates and, for Mini-III, anchor the RNase to the ribosome. These r-proteins thereby serve a quality-control function in the process from accurate ribosome assembly to rRNA processing.

Structures of B. subtilis Maturation RNases Captured on 50S Ribosome with Pre-rRNAs.,Oerum S, Dendooven T, Catala M, Gilet L, Degut C, Trinquier A, Bourguet M, Barraud P, Cianferani S, Luisi BF, Condon C, Tisne C Mol Cell. 2020 Sep 23. pii: S1097-2765(20)30616-X. doi:, 10.1016/j.molcel.2020.09.008. PMID:32991829^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.