CRYSTAL-STRUCTURE OF BACTERIOPHAGE-FR CAPSIDS AT 3.5-ANGSTROM RESOLUTION

The structure of recombinant capsids of the bacterial virus fr has bee n determined by X-ray crystallography at 3.5 Angstrom resolution. The capsids were produced by expressing the fr coat protein in Escherichia coli, the natural host of the virus, and are probably essentially ide ntical to the protein shell of the native virus. The structure was det ermined using molecular replacement with the protein shell of the rela ted MS2 virus, and refined to a crystallographic R-factor of 0.228. A comparison of the protein shells of the viruses shows that they are ve ry similar, and indicates that they may have a similar regulation of t he assembly of the quasi-symmetrical protein shell.