The exosome: a molecular cage for shredding RNAs

Much in the same way as we use shredders to destroy documents that are no longer useful or that contain potentially damaging information, cells use molecular machines to degrade unwanted or defective macromolecules. A key player in the degradation of RNAs is the exosome complex. Our work has revealed how the exosome binds and shreds RNAs by a channeling mechanism that is largely conserved in all kingdoms of life and that parallels the mechanism used by the proteasome to degrade polypeptides.