Phi X 174

This virus was isolated in 1935 by Nicolas Bulgakov [1] in Félix d'Hérelle's laboratory at the Pasteur Institute, from samples collected in Paris sewers.

[2] In 1962, Walter Fiers and Robert Sinsheimer had already demonstrated the physical, covalently closed circularity of ΦX174 DNA.

[3] Nobel prize winner Arthur Kornberg used ΦX174 as a model to first prove that DNA synthesized in a test tube by purified enzymes could produce all the features of a natural virus, ushering in the age of synthetic biology.

[4][5] In 1972–1974, Jerard Hurwitz, Sue Wickner, and Reed Wickner with collaborators identified the genes required to produce the enzymes to catalyze conversion of the single stranded form of the virus to the double stranded replicative form.

[6] In 2003, it was reported by Craig Venter's group that the genome of ΦX174 was the first to be completely assembled in vitro from synthesized oligonucleotides.

Only genes A* and K are thought to be non-essential, although there is some doubt about A* because its start codon could be changed to ATT but not any other sequence.

[14] Phage ΦX174 has been used to try to establish the absence of undiscovered genetic information through a "proof by synthesis" approach.

[14] Infection begins when G protein binds to lipopolysaccharides on the bacterial host cell surface.

Once inside the host bacterium, replication of the [+] ssDNA genome proceeds via negative sense DNA intermediate.

As it translocates around the genome it displaces the outer strand of already-synthesised DNA, which is immediately coated by SSBP proteins.

[citation needed] ΦX174 is also used to test the resistance of personal protective equipment to bloodborne viruses.

[13] The effect of these changes resulted in significantly reduced host attachment, protein expression dysregulation, and heat sensitivity.

Structure of phage ΦX174 capsid
Schematic drawing of a Sins­heimer­virus (aka Phix174­micro­virus ) virion
Genome of the bacteriophage ΦX174 showing its 11 genes [ 10 ]