S-adenosyl-L-methionine-dependent pseudouridine N1-methyltransferase that methylates pseudouridine at position 1248 (Psi1248) in 18S rRNA. It is involved in the biosynthesis of the hypermodified N1-methyl-N3-(3-amino-3-carboxypropyl) pseudouridine (m1acp3-Psi) conserved in eukaryotic 18S rRNA. Is not able to methylate uridine at this position (Wurm et al. 2010).It has also an essential role in 40S ribosomal subunit biogenesis independent of its methyltransferase activity, facilitating the incorporation of ribosomal protein S19 during the formation of pre-ribosomes (By similarity). Part of the small subunit (SSU) processome, the first precursor of the small eukaryotic ribosomal subunit. During the assembly of the SSU processome in the nucleolus, many ribosome biogenesis factors, an RNA chaperone and ribosomal proteins associate with the nascent pre-rRNA and work in concert to generate RNA folding, modifications, rearrangements and cleavage as well as targeted degradation of pre-ribosomal RNA by the RNA exosome
The ribosome assembly factor Nep1 responsible for Bowen-Conradi syndrome is a pseudouridine-N1-specific methyltransferase
Jan Philip Wurm 1, Britta Meyer, Ute Bahr, Martin Held, Olga Frolow, Peter Kötter, Joachim W Engels, Alexander Heckel, Michael Karas, Karl-Dieter Entian, Jens Wöhnert