Ribosomal rNA (rrNA)

The little, medium and large rRNA molecules are all ideal chronometers. They have been establishing to perform the similar function in all known organisms and have regions of conservation as well as hypervariability. The interaction of RNA with ribosomal proteins means which rRNA buried deep within the protein structure is less such to change as any change must also be reflected in the protein sequence. The Changes in either rRNA or ribosomal protein in these regions which lead to an unstable ribosome are lethal to the organism and do not persist in subsequent generations. Moreover, various parts of the rRNA molecules do not have any direct interaction with the ribosomal proteins and so can accumulate mutations much more simply example for are hypervariable.

Of the three rRNA molecules available in prokaryotes like 5S, 16S, and 23S, see Section F5 16S rRNA gives the ideal balance among information content and ease of sequencing. The attractiveness of the molecule is described through the number of entries in the Ribosomal Database Project standing at 1 483 016 Bacterial sequences for release 10 (v23) in December 2010. There are a few drawbacks to the use of the molecule primarily in which many Bacteria have more than one copy of the 16S rRNA gene on their genome frequently with a dissimilar sequence. This can cause confusion and dispute depending on that sequence is used emphasizing the requirement for a polyphasic approach.