RNA methylation RNA capping 7-methylguanosine cap hypermethylation https://github.com/geneontology/go-ontology/issues/26208 m(7)G cap hypermethylation 2012-06-15T02:21:39Z TMG cap formation bf GO:0036261 2,2,7-trimethylguanosine cap formation snRNA capping hypermethylation of snRNA cap biological_process hypermethylation of snoRNA cap snoRNA capping Hypermethylation of the 7-(mono)methylguanosine (m(7)G) cap structure at the 2' position of the guanosine residue to convert a mono-methylated cap to a 2,2,7-trimethylguanosine cap structure. This type of cap modification occurs on small nuclear RNAs (snRNAs) and small nucleolar RNAs (snoRNAs) and is dependent on prior guanine-N7 methylation. conversion of m(7)G to m(3)G