EMG1 (NEP1) methylates a pseudouridine residue in precursor rRNA (pre-rRNA) to yield N(1)-methylpseudouridine (Meyer et al. 2011). Following further modification and nucleolytic processing, the N(1)-methylpseudouridine residue becomes N1-methyl-N3-(3-amino-3-carboxypropyl) pseudouridine-1191 of the 18S rRNA. EMG1 recognizes the nucleotide to be methylated by base-specific interactions with RNA (Thomas et al. 2011). EMG1 is a component of the small subunit processome (SSU processome) a large complex of proteins that binds the 5' region of pre-rRNA, processes and modifies the 18S rRNA, and assists the assembly of the small ribosomal subunit (Bernstein et al. 2004).