2'-''O''-methylation (2'-''O''-Me) is a common
nucleotide
Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...
epitranscriptomics modification of
ribosomal RNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...
(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
Nucleoproteins are proteins conjugated with nucleic acids (either DNA or RNA). Typical nucleoproteins include ribosomes, nucleosomes and viral nucleocapsid proteins.
Structures
Nucleoproteins tend to be positively charged, facilitating inter ...
(snoRNP)
where a
methyl group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula ). In formulas, the group is often abbreviated a ...
is added to the
2' hydroxyl of the
ribose
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally occurring form, , is a component of the ribonucleotides from which RNA is built, and so this comp ...
moiety of any nucleotide (Nm) producing a
methoxy
In organic chemistry, a methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula .
On a benzene ring, the Hammett equation classifies a methoxy substituent at the ''para'' position a ...
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
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...
and
small nuclear RNA
Small nuclear RNA (snRNA) is a class of small RNA molecules that are found within the Cell nucleus#Splicing speckles, splicing speckles and Cajal body, Cajal bodies of the cell nucleus in eukaryotic cells. The length of an average snRNA is approxi ...
located in the
ribosome
Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order s ...
and
spliceosome
A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs ( snRNA) and numerous proteins. Small nuclear RNA (snRNA) molecules bind to sp ...
. 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.
See also
*
Nucleic acid analogue
*
Small nucleolar RNA
References
{{DEFAULTSORT:2'-O-methylation
RNA
O-methylation