5S ribosomal RNA

5S ribosomal RNA (5S rRNA) is a component of the large ribosomal subunit in both prokaryotes and eukaryotes.


 * In prokaryotes, it is part of the 50S subunit.
 * In eukaryotes, it is synthesised by RNA polymerase III (the other eukaryotic rRNAs are cleaved from a 45S precursor synthesized by RNA polymerase I). In Xenopus oocytes, it has been shown that fingers 4-7 of the nine-zinc finger transcription factor TFIIIA can bind to the central region of 5S RNA. Thus, in addition to positively regulating 5S rRNA transcription, TFIIIA also stabilizes 5S rRNA until it is required for transcription.