title: Localization of coliphage MS2 A-protein.
abstract: The purification of coliphage MS2 dinitrophenol (DNP) conjugates provided a system for localization of the single molecule of A-protein in the capsid of the MS2 phage particle. Three A-protein preparations isolated from unconjugated MS2, overconjugated DNP-MS2, and purified 78S DNP-MS2 were tested for the presence of covalently bound DNP. The binding characteristics to Dowex 1-X8 and rabbit anti-DNP bovine serum albumin (DNP-BSA) immunoglobulin G of the 78S DNP-MS2 and overconjugated DNP-MS2 A-protein preparations indicate that the A-protein is located on the surface of the phage particle where it can be covalently conjugated with hapten. Extensive enzymatic iodination of the A-protein of intact unconjugated MS2 substantiates this conclusion.
mesh_terms: D003090:Coliphages / Q000032:analysis*; D004140:Dinitrophenols; D004589:Electrophoresis, Disc; D006639:Histidine; D007457:Iodine Radioisotopes; D011485:Protein Binding; D012328:RNA Viruses / Q000032:analysis; D011863:Radioimmunoassay; D012967:Sodium Dodecyl Sulfate; D014316:Tritium; D014764:Viral Proteins / Q000032:analysis*
chemical_list: D004140:Dinitrophenols; D007457:Iodine Radioisotopes; D014764:Viral Proteins; D014316:Tritium; D012967:Sodium Dodecyl Sulfate; D006639:Histidine