Send to

Choose Destination
Cell. 1990 Feb 9;60(3):405-14.

The excision of intervening sequences from Salmonella 23S ribosomal RNA.

Author information

Department of Biology, Indiana University, Bloomington 47405.


Novel, approximately 90 bp intervening sequences (IVs) were discovered within the 23S rRNA genes of S. typhimurium and S. arizonae. These non-rRNA sequences are transcribed and then excised during rRNA maturation. The rRNA fragments that result from the excision of the extra sequences are not religated. This results in fragmented 23S rRNAs. The excision of one IVS was shown to be catalyzed in vivo and in vitro by ribonuclease III. These IVSs are highly volatile evolutionarily, sometimes occurring in only some of the multiple rRNA operons of a particular cell. The sporadic nature of the occurrence of fragmented rRNAs among closely related organisms argues that such fragmentation is a derived state, not a primitive one. Possible sources of these IVSs, their parallels with internal transcribed spacers and introns in eukaryotes, and their possible roles in the evolutionary process are discussed.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center