Mutagenesis of the peptidyltransferase center of 23S rRNA: the invariant U2449 is dispensable
AUTOR(ES)
O’Connor, Michael
FONTE
Oxford University Press
RESUMO
U2449 is one of many invariant residues in the central loop of domain V of 23S rRNA, a region that constitutes part of the peptidyltransferase center of the ribosome. In Escherichia coli, this U is post-transcriptionally modified to dihydrouridine (D) and is the only D modification found in E.coli rRNAs. To analyze the role of this base and its modification in ribosomal function, all three base substitutions were constructed on a plasmid copy of the rrnB operon and assayed for their ability to support cell growth in a strain of E.coli lacking chromosomal rrn operons. Both purine substitution mutations were not viable. However, growth and antibiotic sensitivity of cells expressing only the mutant D2449C rRNA was indistinguishable from wild type. We conclude that while a pyrimidine is required at position 2449 for proper ribosomal function, the D modification is dispensable.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=30386Documentos Relacionados
- Functional interactions within 23S rRNA involving the peptidyltransferase center.
- The "DEAD box" protein DbpA interacts specifically with the peptidyltransferase center in 23S rRNA.
- Lessons from an evolving rRNA: 16S and 23S rRNA structures from a comparative perspective.
- Sequence homologies between eukaryotic 5.8S rRNA and the 5' end of prokaryotic 23S rRNa: evidences for a common evolutionary origin.
- Identification of a region in 23S rRNA located at the peptidyl transferase center.