Staphylococcus aureus domain V functions in Escherichia coli ribosomes provided a conserved interaction with domain IV is restored

Abstract

Domain V of Escherichia coli 23 S rRNA (residues 2023-2630) was replaced by that from Staphylococcus aureus, thereby introducing 132 changes in the rRNA sequence. The resulting ribosomal mutant was unable to support cell growth. The mutant was rescued, however, by restoring an interaction between domains IV and V (residues 1782 and 2586). Although the importance of this interaction, U/U in E. coli, C/C in S. aureus, is therefore demonstrated, it cannot be the only tertiary interaction important for ribosomal function as the rescued hybrid grew more slowly than the wild type. Additionally, although the single-site mutations U1782C and U2586C in E. coli are viable, the double mutant is lethal.

The presence of highly disruptive 16S rRNA mutations in clinical samples indicates a wider role for mutations of the mitochondrial ribosome in human disease

“…This is because the protonation of the N1 of 1026A would disrupt the reverse Hoogsteen configuration ( Pan et al, 1998 , Saenger, 1984 ). The loss of base pairing interactions in the neighbourhood of this triple base interaction was demonstrated to be highly detrimental to ribosomal function by mutagenesis in bacteria (specifically, residues 2025 and 2026 ) ( O'Connor, 2007 , Thompson et al, 2001a ). Notably, mutations at the adjacent G2032 of the bacterial ribosome are known to cause resistance to the oxazolidinone antibiotic linezolid ( Kloss et al, 2000 ).…”

Structure of the Ribosome

“…The domains form structural units, as the vast majority of interactions involving two or more hydrogen bonds occur within domains, rather than between them. This is also the reason for that the interchange of the domain V from E. coli against Staphylococcus aureus in the 23S rRNA of E. coli was possible, even though it introduces 132 changes into the E. coli rRNA sequence, only one additional mutation of U1782C for was necessary for viability [57].…”

Selection for intragenic suppressors of lethal 23S rRNA mutations in Escherichia coli identifies residues important for ribosome assembly and function

“…1) and may aVect the packing of adjacent RNA helices. Previously, disruption of two base pairs (G2024-U2039 and C2025-G2038) was shown to be lethal and the single C2025U mutant was shown to be temperature sensitive (Thompson et al 2001b).…”