![Graphic illustrating how chaperonin subunits that fail to assemble, either because they are orphan subunits or because assembly if incomplete, are routed for degradation by the ubiquitin ligase HERC2 and adapter ZNRD2.](https://www2.mrc-lmb.cam.ac.uk/wordpress/wp-content/uploads/Hegde_chaperonin_AssemblyQC_Thumbnail_image-150x150.jpg)
Cells eliminate “orphan” proteins that have failed to assemble into the molecular machines within which they normally function. Manu Hegde’s group have now elucidated the mechanism by which one type of orphan is selectively recognised and tagged for destruction.