Chemical evidence for the capsomeric structure of phage q beta.

Novel capsomeric complexes, pentamers and hexamers were detected as chemical entities in phage Q beta. Both were composed of identical protein subunits and stabilized by intermolecular disulphide bonds. Their numbers per particle were about 12 for pentamers and about 20 for hexamers--consistent with theoretical expectation from the quasi-equivalent packing of 180 identical subunits in a coat protein shell.