Structural Basis for the Activation of the Deubiquitinase Calypso by the Polycomb Protein ASX

？ The DmPR-DUB structure reveals molecular details of Calypso interactions with ASX ？ Ub binding by DmPR-DUB resembles the binding observed in the UCHL5-RPN13-Ub complex ？ ASX-Ub contacts and stabilization of the crossover loop activate Calypso ？ Cancer mutations of BAP1 and ASXL1 affect Ub binding and BAP1 activation by ASXL