This superfamily represents the N-terminal domain of the ribosomal RNA-processing protein 8 (RRP8). Rrp8 is a nucleolar methyltransferase with a Rossman-like fold. In yeast, it is involved in pre-rRNA cleavage at site A2 and is responsible for a base methylation of the 25S rRNA. In humans it is also known as nucleomethylin (NML), and it is important for mediating the assembly of the energy-dependent nucleolar silencing complex (eNoSC), which regulates rRNA transcription in response to glucose deprivation. NML represses rDNA transcription by promoting H3K9 methylation and establishing heterochromatin across the rDNA.

PFAM:PF05148, INTERPRO:IPR042036,PMID:10864042,PMID:23180764,PMID:23897426,PMID:18485871