The site for peptide bond formation in the ribosomes, the PTC, is located within a highly conserved internal pocket made exclusively of rRNA. The high conservation implies its existence irrespective of environmental conditions and indicates that it may represent a prebiotic RNA machine, which could be the kernel around which life originated. Lab constructs imitating this pocket possess capabilities for peptide bond formations, thus indicating that a molecular prebiotic bonding entity still exists and functions within ribosomes of all living cells.
In contrast, other ribosomal components undergo genetic variability that led to the creation of specific structural features. Among them, those related to ribosomal genetic diseases, or specific to antibiotics resistant pathogens, are being used as bases for the design of RNA based next generation therapeutics.