| Group I (dsDNA)|
| Siphoviridae, Caudovirales, Podoviridae, Phycodnaviridae, Myoviridae|
Phic3unalikevirus (synonym PhiC31-like viruses) is a genus of viruses in the order Caudovirales, in the family Siphoviridae. Bacteria serve as natural hosts. There are currently three species in this genus including the type species Streptomyces phage phiC31.
Phic3unalikeviruses are nonenveloped, with a head and tail. The head is about 53 nm in diameter, consisting of 72 capsomers. The tail is long and flexible, at about 100 nm long, 5 nm wide, has a 15 nm wide baseplate and four tail fibers ended by terminal knobs.
Streptomyces phage phiC31 has been fully sequenced. It has about 41k nucleotides, with 53 proteins. The complete genome, as well as two similar but unclassified strains, are available here
Viral replication is cytoplasmic. The virus attaches to the host cell's adhesion receptors using its terminal fibers, and ejects the viral DNA into the host cytoplasm via long flexible tail ejection system. Replication follows the replicative transposition model. DNA-templated transcription is the method of transcription. Once the viral genes have been replicated, the procapsid is assembled and packed. The tail is then assembled and the mature virions are released via lysis. Bacteria serve as the natural host. Transmission routes are passive diffusion.
According to ICTV, the genus Phic3unalikevirus was first accepted under the name PhiC31-like viruses in 2004, assigned to family Siphoviridae in order Caudovirales. In 2012, the genus was renamed to Phic3unalikevirus.