Nuclear RIOX2 (Bifunctional lysine-specific demethylase and histidyl-hydroxylase MINA) 3-hydroxylates histidine 39 of RPL27A (60S ribosomal protein L27a) (Ge et al. 2012). The oligomerization state of RIOX2 in vivo is unknown; it is annotated here as a monomer complexed with one Fe2+ ion (Brauer et al. 2018).