Pyrococcus C/D box small nucleolar RNA

Pyrococcus C/D box small nucleolar RNA are non-coding RNA (ncRNA) molecules identified in the archaebacteria Pyrococcus abyssi which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifiying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. This type of ncRNAs are known as small nucleolar RNAs (snoRNA) and also often referred to as a guide RNAs.

Computational screens of archaebacterial genomes have identified C/D box snoRNAs in a number of archaeal genomes. In particular 46 small RNAs were identified to be conserved in the genomes of three hyperthermophile Pyrococcus species. These putative snoRNAs differ from their eukaryotic homologs by their outstanding structural homogeneity, extended consensus box motifs and the quasi-systematic presence of two (instead of one) rRNA antisense elements.