3.4.11.B8 dodecamer the enzyme assembles as a 12-subunit tetrahedron and as a 24-subunit octahedral particle. The internal organization of the PhTET1 particles reveals highly self-compartmentalized systems made of networks of access channels extended by vast catalytic chambers. The two edifices display aminopeptidase activity. Compared with the tetrahedron, the octahedron forms a more expanded hollow structure, representing a new type of giant peptidase complex -, 745279 3.4.11.B8 dodecamer the quaternary structures of PhTET1 reveal an elaborated self-compartmentalized organization for a peptidase complex. The enzyme assembles as a 12-subunit tetrahedron and as a 24-subunit octahedral particle. Compared with the tetrahedron, the octahedron forms a more expanded hollow structure, representing a new type of giant peptidase complex. PhTET1 assembles into two different quaternary structures because of quasi-equivalent contacts previously identified in viral capsids. The dodecameric complex is in general more active than the 24-subunit edifice -, 745279 3.4.11.B8 tetracosamer the enzyme assembles as a 12-subunit tetrahedron and as a 24-subunit octahedral particle. The internal organization of the PhTET1 particles reveals highly self-compartmentalized systems made of networks of access channels extended by vast catalytic chambers. The two edifices display aminopeptidase activity. Compared with the tetrahedron, the octahedron forms a more expanded hollow structure, representing a new type of giant peptidase complex -, 745279 3.4.11.B8 tetracosamer the quaternary structures of PhTET1 reveal an elaborated self-compartmentalized organization for a peptidase complex. The enzyme assembles as a 12-subunit tetrahedron and as a 24-subunit octahedral particle. Compared with the tetrahedron, the octahedron forms a more expanded hollow structure, representing a new type of giant peptidase complex. PhTET1 assembles into two different quaternary structures because of quasi-equivalent contacts previously identified in viral capsids. The dodecameric complex is in general more active than the 24-subunit edifice -, 745279