Structural and functional roles of 2′-O-ribose methylations and their enzymatic machinery across multiple classes of RNAs

RNA complexity is augmented by numerous post transcriptional modifications, which influence RNA function by modulating its structure and interactome. One prominent modification is methylation at the ribose 2'-hydroxyl group. 2'-O-methylation has been found in all RNA classes, with rRNA and tRNA being extensively modified. The exact function of 2'-O-methylation at specific RNA sites is still not understood, with a few notable exceptions. The relevance of 2'-O-methylation for cell survival and well-being is proven by the large effort that the cell spends in maintaining a diverse and highly regulated methylation machinery. Here, we review the current knowledge on the impact of 2'-O-methylation on structure and function of different RNAs as well as on the factors determining substrate specificity in the enzymatic machinery.