APC/C is an E3 ligase complex of ~1.5 MDa that regulates cell division. APC/CCDH1 is inhibited during interphase by EMI1. Now, NMR spectroscopy, electron microscopy and enzymology analyses are integrated, revealing that EMI1's 143-residue C-terminal domain binds distinct regions of APC/CCDH1 to block the substrate-binding site and inhibit ubiquitin-chain elongation.
- Jeremiah J Frye
- Nicholas G Brown
- Brenda A Schulman
