RRC ID 53728
Author Nord S, Bhatt MJ, Tükenmez H, Farabaugh PJ, Wikström PM.
Title Mutations of ribosomal protein S5 suppress a defect in late-30S ribosomal subunit biogenesis caused by lack of the RbfA biogenesis factor.
Journal RNA
Abstract The in vivo assembly of ribosomal subunits requires assistance by maturation proteins that are not part of mature ribosomes. One such protein, RbfA, associates with the 30S ribosomal subunits. Loss of RbfA causes cold sensitivity and defects of the 30S subunit biogenesis and its overexpression partially suppresses the dominant cold sensitivity caused by a C23U mutation in the central pseudoknot of 16S rRNA, a structure essential for ribosome function. We have isolated suppressor mutations that restore partially the growth of an RbfA-lacking strain. Most of the strongest suppressor mutations alter one out of three distinct positions in the carboxy-terminal domain of ribosomal protein S5 (S5) in direct contact with helix 1 and helix 2 of the central pseudoknot. Their effect is to increase the translational capacity of the RbfA-lacking strain as evidenced by an increase in polysomes in the suppressed strains. Overexpression of RimP, a protein factor that along with RbfA regulates formation of the ribosome's central pseudoknot, was lethal to the RbfA-lacking strain but not to a wild-type strain and this lethality was suppressed by the alterations in S5. The S5 mutants alter translational fidelity but these changes do not explain consistently their effect on the RbfA-lacking strain. Our genetic results support a role for the region of S5 modified in the suppressors in the formation of the central pseudoknot in 16S rRNA.
Volume 21(8)
Pages 1454-68
Published 2015-8-1
DOI 10.1261/rna.051383.115
PII rna.051383.115
PMID 26089326
PMC PMC4509935
MeSH Bacteria / classification Bacteria / genetics Bacteria / growth & development* Bacteria / metabolism Bacterial Proteins / genetics Bacterial Proteins / metabolism Genes, Lethal Models, Molecular Mutation Protein Structure, Secondary RNA, Bacterial / metabolism RNA, Ribosomal, 16S / metabolism* Ribosomal Proteins / chemistry Ribosomal Proteins / genetics Ribosomal Proteins / metabolism* Ribosome Subunits, Small, Bacterial / metabolism
IF 4.32
Times Cited 2
Resource
Prokaryotes E. coli