Cellular component

A conserved RNA endonuclease complex required for spreading and epigenetic inheritance of heterochromatin. The rixosome contains six unique subunits: three structural subunits (Crb3, Rix1, and Ipi1) which form the core of the complex, and three catalytic subunits (the endonuclease Las1, the polynucleotide kinase Grc3, and the AAA-type ATPase Mdn1), which are involved in the processing of ribosomal RNA precursors. All subunits are essential for viability and are conserved from yeast to mammals, including humans.