The process of infection with bacteriophage φX174. XVIII. Intracellular Antiserum-precipitable Components

Components precipitable by antiserum to bacteriophage φX174 can be derived from φX-infected cells. Antiserum-precipitable ^(35)S is found in three peaks after zone sedimentation in sucrose gradients. The fastest sedimenting peak is infective virus; the intermediate peak is the non-infective 70 s component. The slowest component was studied in greater detail and has the following properties. It has a sedimentation coefficient of about 6; in a thymine-requiring host, the material accumulates in the absence of thymidine; the accumulated material is subsequently incorporated into virus when thymidine is restored. The 6 s material is, therefore, considered to be a subunit of the virus structure. The φX double mutant am3tsγ, which does not make whole virus under restrictive conditions, forms a subunit which appears to have similar sedimentation properties to that of the wild type