This is a methyltransferase that depends on S-adenosyl-L-methionine,
capable of methylating both RNA and proteins. It plays a role in pre-rRNA
processing by performing site-specific 2'-hydroxyl methylation on ribose
moieties in pre-ribosomal RNA (
Schimmang et al. 1989,
Tollervey et al. 1991,
Galardi et al. 2002).
The specificity of the methylation site is determined by a guide RNA that pairs with the substrate,
with the methylation occurring at a characteristic distance from the sequence involved in base pairing
(
Schimmang et al. 1989,
Tollervey et al. 1991).
This enzyme is also involved in the biogenesis of 18S rRNA.
Furthermore, it functions as a protein methyltransferase, catalyzing the methylation of histone
H2A's 'Gln-105' (H2AQ105me). This modification impairs binding of the FACT complex and is specifically
present at the 35S ribosomal DNA locus (
Schimmang et al. 1989,
Tollervey et al. 1991).
It is the catalytic subunit of a multiprotein C/D RNP complex. Works in S. cerevisiae with 3 other proteins: Nop58p, Nop56p, Snu13p. About 53 positions methylated by C/D RNP complex were found in S. cerevisiae rRNA