Cryo-EM shows reciprocal and conformational regulation of APC/CCDC20 and MCC
MCC blocks APC/CCDC20-binding sites for substrates such as Cyclins and Securin
Closed APC/CCDC20-MCC blocks E2 UBE2C, as during the spindle checkpoint
Open APC/CCDC20-MCC directs ubiquitination of MCC, as during checkpoint silencing