Reaction: Box C/D snoRNP methylates ribonucleotides in pre-rRNA yielding 2'-O-methylribonucleotides
- in pathway: rRNA modification in the nucleus and cytosol
The Fibrillarin (FBL) component of Box C/D small nucleolar ribonucleoprotein complexes (snoRNPs) transfers a methyl group from s-adenosylmethionine to the 2' hydroxyl group of ribonucleotides in precursor rRNAs (pre-rRNAs) in the nucleolus (Maden and Hughes 1997, inferred from mouse homologs in Cavaille and Bachellerie 1998, and inferred from homologues in Saccharomyces cerevisiae). The box C/D snoRNA component of the complex guides the methylation by base pairing with 10-21 nucleotide regions of the pre-rRNA (Filippova et al. 2015, inferred from mouse homologs in Cavaille and Bachellerie 1998). The protein components of the core box C/D snoRNP are FBL (homologous to NOP1 in yeast), NOP56, NOP58, and NHP2L1 (15.5K, homologous to SNU13 of yeast) (Lyman et al. 1999, Watkins et al. 2000, Watkins et al. 2002, Schultz et al. 2006, McKeegan et al. 2007). More than 100 nucleotide positions in human rRNAs are 2'-O-methylated and the human genome encodes more than 250 box C/D snoRNAs (Lestrade and Weber 2006), which are 50-300 nucleotides in length and contain box C (RUGAGA) and box D (CUGA) elements.
Reaction - small molecule participants:
AdoHcy [nucleoplasm]
AdoMet [nucleoplasm]
Reactome.org reaction link: R-HSA-6790907
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Reaction input - small molecules:
S-adenosyl-L-methionine zwitterion
Reaction output - small molecules:
S-adenosyl-L-homocysteine zwitterion
Reactome.org link: R-HSA-6790907