RlmJ is ribosomal RNA large subunit methyltransferase J is required for full methylation of 23S ribosomal RNA (rRNA) during ribosome biogenesis. The ribosomal RNA of E. coli carries 24 residues that require methylation, and this methyltransferase is the last to be described, that modifies A2030 [1]. RlmJ displays a variant of the Rossmann-like methyltransferase (MTase) fold with an inserted helical subdomain. On binding cofactor and substrate a large shift of the N-terminal motif X tail is induced in order to make it cover the cofactor-binding site and to trigger active-site changes in motifs IV and VIII [2].

1: The last rRNA methyltransferase of E. coli revealed: the yhiR gene encodes adenine-N6 methyltransferase specific for modification of A2030 of 23S ribosomal RNA. Golovina AY, Dzama MM, Osterman IA, Sergiev PV, Serebryakova MV, Bogdanov AA, Dontsova OA; RNA. 2012;18:1725-1734. PMID:22847818

2: Structural and functional insights into the molecular mechanism of rRNA m6A methyltransferase RlmJ. Punekar AS, Liljeruhm J, Shepherd TR, Forster AC, Selmer M; Nucleic Acids Res. 2013; [Epub ahead of print] PMID:23945937