Updated project metadata. Cellular RNAs are covalently modified and these modifications can impact on all biological processes and hence are implicated in different types of diseases. Amongst RNA modifications, N6-methyladenosine (m6A) is one of the most widespread and has been found on messenger (mRNA), ribosomal (rRNA), non-coding and spliceosomal RNAs. We undertook a systematic screen to uncover new RNA-methyltransferases. We demonstrate that the methyltransferase-like 5 protein (METTL5) is an 18S rRNA specific methyltransferase and interacts specifically with Trmt122.