Three phages in this genus (φKZ, φPA3, and 201φ2-1) are known to assemble a "phage nucleus" structure similar in function to the eukaryotic cell nucleus that encloses DNA as well as replication and transcription machinery.

It provides immunity to host defenses like restriction enzymes and CRISPR-Cas systems.

[4] The following three species are assigned to the genus:[2] Phikzviruses are nonenveloped, with a head and tail.

The head has icosahedral symmetry (T=27), with a relatively large diameter of about 140  nm.

Once the viral genes have been replicated, the procapsid is assembled and packed.