Construction of recombinant viruses. (A) The genome of HSV-1, including the US6 (gD), US7 (gI), and US8 (gE) genes, is depicted (44). (i) The insertion of stop codons in the gE CT domain after residues 448, 470, 495, and 519 was previously described (23). (ii) A kanamycin resistance gene cassette was inserted into the coding sequences of gD, and this was transferred into BACs containing truncated versions of gE. (B) Vero cells were infected with F-BAC gD−, F-BAC gD−/gE519, F-BAC gD−/gE495, F-BAC gD−/gE470, F-BAC gD−/gE448, F-BAC gD−/gE−, or wild-type F-BAC HSV-1 (w.t.). The cells were labeled with [35S]methionine-cysteine, and gB, gD, or gE was immunoprecipitated from cell extracts by using MAb 15βB2, DL6, or 3114, respectively. The positions of gB, gD, and gE are indicated on the right side of the panel.