The structure of cowpea mosaic virus complexed with 60, 1.4 nanometer, gold particles attached to specific cysteine residues on the particle surface. The structure was created by genetic engineering of the virus capsid subunits. The proteins of the virion are represented as ribbon drawings that show the location and fold of the 60 pairs of polypeptide chains that form the virus. The specific pattern of gold particles demonstrates that this virus can be used to generate attachment sites for creating new surface properties that may be useful in developing novel biomaterials.