Ribosomal RNAs are tolerant toward genetic insertions: evolutionary origin of the expansion segments.

ABSTRACT: Ribosomal RNAs (rRNAs), assisted by ribosomal proteins, form the basic structure of the ribosome, and play critical roles in protein synthesis. Compared to prokaryotic ribosomes, eukaryotic ribosomes contain elongated rRNAs with several expansion segments and larger numbers of ribosomal proteins. To investigate architectural evolution and functional capability of rRNAs, we employed a Tn5 transposon system to develop a systematic genetic insertion of an RNA segment 31 nt in length into Escherichia coli rRNAs. From the plasmid library harboring a single rRNA operon containing random insertions, we isolated surviving clones bearing rRNAs with functional insertions that enabled rescue of the E. coli strain (Delta7rrn) in which all chromosomal rRNA operons were depleted. We identified 51 sites

SUBMITTER: Yokoyama T 

PROVIDER: S-EPMC2441807 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature