A key question in the ubiquitin-proteasome system is how E3 ligases select their substrates. Here, the authors reveal that CRL2FEM1B E3 ligase functions as a dimer and employs a bipartite mode of substrate recognition, requiring a C-terminal proline and an upstream aromatic residue in the target.
- Xinyan Chen
- Anat Raiff
- Chao Xu