This is the THUMP-like domain of Ribosomal RNA large subunit methyltransferase M (RLMM), adjacent the ferredoxin-like domain (Pfam:PF18125), which together constitutes the N-terminal domain [1]. RlmM specifically catalyses the 2'-O-methylation of nucleotide C2498 in the peptidyl transferase loop of 23S rRNA [1].

1: Crystal structure of RlmM, the 2'O-ribose methyltransferase for C2498 of Escherichia coli 23S rRNA. Punekar AS, Shepherd TR, Liljeruhm J, Forster AC, Selmer M; Nucleic Acids Res. 2012;40:10507-10520. PMID:22923526