Assembly protease promotes icosahedral procapsid assembly. Autocatalytic cleavage may release the capsid scaffolding protein. The protease domain catalyzes the cleavage of the capsid scaffolding protein after complete procapsid formation. Assembly protease and cleavages products are evicted from the capsid before or during DNA packaging. Scaffolding protein Nu3 promotes icosahedral procapsid assembly. Acts by binding the major capsid protein gpE and multimerizing in interaction with portal dodecamer, thereby placing gpE in a context facilitating icosahedral procapsid formation. Cleaved by capsid assembly protease C after capsid completion. The cleavages products are evicted from the capsid before or during DNA packaging. Capsid assembly protease interacts with capsid scaffolding protein Nu3. Capsid scaffolding protein Nu3 multimerizes and interacts with major capsid protein gpE. It is uncertain wether Val-260 or Met-309 is the initiator for Capsid scaffolding protein Nu3. Produced by alternative initiation at Met-309 of isoform. Belongs to the peptidase S49 family. Some of the E protein may be covalently linked with an equimolar amount of protein C and cleaved to yield minor capsid proteins X1 and X2. But recent data fail to detect cleavages products.