2'-O-methylation

2'-O-methylation (2'-O-Me) is a common nucleotide epitranscriptomics modification of ribosomal RNA (rRNA). The rRNA is transcribed from DNA and then used to create proteins through translation. The resulting protein would normally be solely dependent on the gene it was translated from, but the methylation of the RNA would influence the outcome of the protein as well. This modification to the rRNA is done via ribonucleoprotein (snoRNP) where a methyl group is added to the 2' hydroxyl of the ribose moiety of any nucleotide (Nm) producing a methoxy group. The modification of one Nm creates more stabilization in the structure by 0.2kcal/mol which is more enthalpically favorable. 2'-O-methylated nucleotides are mostly found in post-translational ribosomal RNA and small nuclear RNA located in the ribosome and spliceosome. Currently, about 55 2'-O-methylations have been identified in yeast alone and 106 in humans and deposited in RNA Modification Base (RMBase) database.

This modification is able to stabilize the structure of RNA while preventing it from undergoing hydrolysis as the hydroxyl group is replaced. A technique was developed based on this property called RiboMethSeq to quantify the amount of modifications existing in a sample of rRNA. RNA is a short lived molecule and each of the types vary in its longevity in the cell. Ribosomal RNA exists longer in the cell before degradation so utilizing 2'-O-Met would aid in stabilizing its structure. The epitranscriptomics of this particular RNA modification occurs post-translation, causing a change in the resulting protein without the DNA being altered.

Having chemical properties intermediate between RNA and DNA, 2'-O-methylation is presumed to have been one of the reactive group of RNA molecules on early Earth that would have given rise to DNA.