| Namespace | cellular_component | Obsolete | false |
| description | A ribonucleoprotein complex containing a box C/D type RNA that is capable of ribose-2'-O-methylation of target RNAs. Box C/D type RNAs are widespread in eukaryotes and in Archaea, suggesting that an RNA-based guide mechanism for directing specific RNA 2'-O-ribose methylations was present in the common ancestor of Archaea and Eukarya. |