Mini‐III, an unusual member of the RNase III family of enzymes, catalyses 23S ribosomal RNA maturation in B. subtilis
- 21 April 2008
- journal article
- Published by Wiley in Molecular Microbiology
- Vol. 68 (5), 1096-1106
- https://doi.org/10.1111/j.1365-2958.2008.06207.x
Abstract
The late steps of both 16S and 5S ribosomal RNA maturation in the Gram-positive bacterium Bacillus subtilis have been shown to be catalysed by ribonucleases that are not present in the Gram-negative paradigm, Escherichia coli. Here we present evidence that final maturation of the 5' and 3' extremities of B. subtilis 23S rRNA is also performed by an enzyme that is absent from the Proteobacteria. Mini-III contains an RNase III-like catalytic domain, but curiously lacks the double-stranded RNA binding domain typical of RNase III itself, Dicer, Drosha and other well-known members of this family of enzymes. Cells lacking Mini-III accumulate precursors and alternatively matured forms of 23S rRNA. We show that Mini-III functions much more efficiently on precursor 50S ribosomal subunits than naked pre-23S rRNA in vitro, suggesting that maturation occurs primarily on assembled subunits in vivo. Lastly, we provide a model for how Mini-III recognizes and cleaves double-stranded RNA, despite lacking three of the four RNA binding motifs of RNase III.Keywords
This publication has 40 references indexed in Scilit:
- Differences in substrate selectivities of the SPOUT superfamily of methyltransferasesNucleic Acids Symposium Series, 2007
- Ribonuclease revisited: structural insights into ribonuclease III family enzymesCurrent Opinion in Structural Biology, 2006
- Characterization of RNA sequence determinants and antideterminants of processing reactivity for a minimal substrate of Escherichia coli ribonuclease IIINucleic Acids Research, 2006
- Structural Insight into the Mechanism of Double-Stranded RNA Processing by Ribonuclease IIICell, 2006
- Subcellular Localization of a Small Sporulation Protein inBacillus subtilisJournal of Bacteriology, 2003
- Ribonuclease M5 Has Few, If Any, mRNA Substrates in Bacillus subtilisJournal of Bacteriology, 2002
- Nontemplated Nucleotide Addition by HIV-1 Reverse TranscriptaseBiochemistry, 2002
- Immature 50 S subunits in Escherichia Coli polyribosomesFEBS Letters, 1978
- Cleavage by ribonuclease III of the complex of 30 S pre-ribosomal RNA and ribosomal proteins of Escherichia coliJournal of Molecular Biology, 1975
- Study of the maturation of 5 s RNA precursors in Escherichia coliJournal of Molecular Biology, 1972