2'-O-methylation

2'-O-methylation (2'-O-Me) is a nucleotide epitranscriptomics modification commonly found in ribosomal RNA (rRNA), transfer RNA (tRNA), and small nuclear RNA (snRNA).^[1] This modification is created through post-transcriptional modification of the RNA.^[2] This modification can be performed via ribonucleoprotein (snoRNP) with C/D box small nucleolar RNA (snoRNA) used as a guide RNA^[3] where a methyl group is added to the 2' hydroxyl of the ribose moiety of any nucleotide (Nm)^[4] producing a methoxy group. It can also be performed through other enzymes without a guide RNA such as FTSJ1 in tRNAs.^[1] The modification of one Nm creates more stabilization in the structure by 0.2kcal/mol^[5] which is more enthalpically favorable. Currently, about 55 2'-O-methylations have been identified in yeast alone and 106 in humans^[6] and deposited in RNA Modification Base (RMBase) database.^[7]

2'-O-methyl-adenosine, a modified adenosine.

This modification is able to stabilize the structure of RNA while preventing it from undergoing hydrolysis as the hydroxyl group is replaced.^[3] A technique was developed based on this property called RiboMethSeq to quantify the amount of modifications existing in a sample of rRNA.^[8] 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.^[9]

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.^[10]

See also

• Nucleic acid analogue
• Small nucleolar RNA