Radioimmunoprecipitation of F and H polypeptides of RPV expressed by rVVs. Lane 1, cells infected with v2RVFH expressing both F and H genes of RPV under the control of strong synthetic promoters (dsP); lane 2, cells infected with vRVFH expressing both F and H genes under control of the P7.5 promoters; lane 3, cells infected with vRVH expressing only the H gene under control of the P7.5 promoter; lane 4, cells infected with vRVF expressing only the F gene under control of the P7.5 promoter; lane 5, cells infected with the wild-type Copenhagen strain of VV; and lane 6, molecular size standards (shown in kilodaltons).