NSUN5 (and the homologue from yeast RCM1) is a SAM-dependent methyltransferase that specifically methylates the C(5) position of cytosine 3782 in 28S rRNA [2,3]. This is the N-terminal globular domain of NSUN5 which is required for targeting to nucleoli [2].

1: Yeast Nop2 and Rcm1 methylate C2870 and C2278 of the 25S rRNA, respectively. Sharma S, Yang J, Watzinger P, Kotter P, Entian KD; Nucleic Acids Res. 2013;41:9062-9076. PMID:23913415

2: Loss of the ribosomal RNA methyltransferase NSUN5 impairs global protein synthesis and normal growth. Heissenberger C, Liendl L, Nagelreiter F, Gonskikh Y, Yang G, Stelzer EM, Krammer TL, Micutkova L, Vogt S, Kreil DP, Sekot G, Siena E, Poser I, Harreither E, Linder A, Ehret V, Helbich TH, Grillari-Voglauer R, Jansen-Durr P, Kos M, Polacek N, Grillari J, Schosserer M; Nucleic Acids Res. 2019;47:11807-11825. PMID:31722427