IgG also plays an important role in antibody-dependent cell-mediated cytotoxicity (ADCC) and intracellular antibody-mediated proteolysis, in which it binds to TRIM21 (the receptor with greatest affinity to IgG in humans) in order to direct marked virions to the proteasome in the cytosol.
Intracellular antibody-mediated degradation (IAMD) is a neutralization mechanism of intracellular antibody-mediated immunity whereby an effector protein, TRIM21, directs antibody bound virions to the proteasome where they are degraded.
Virions are encapsulated, non-enveloped, elongated and shows polyhedral symmetry with a length of 26–76 nm and a width of 18–26 nm.
The virions contain significant amounts of double-stranded full-length DNA, and assembly is rather unusual in these viruses.