Exosome complex

The exosome complex is a protein complex which can degrade RNA strands (~stop them working). In eukaryotic cells, the exosome complex is present in the cytoplasm, nucleus, and especially the nucleolus. 
The core of the complex has a ring structure consisting of six proteins that all belong to the same class of RNases, the 'RNase PH-like proteins'.
Exosome complexes are found in both eukaryotic cells and archaea. In bacteria a simpler complex called the "degradosome" carries out similar functions.