FIG. 1.
(A) Southern blot of wild-type, gE mutant, and rescued viruses. NS, NS-gEnull, rNS-gEnull, NS-gE339, rNS-gE339, and NS-gE406 were digested with NruI alone (lanes 1 to 6) or with NruI and XhoI to detect XhoI linkers in NS-gE339 and NS-gE406 (lanes 7 to 12). The blot was probed with a 1.1-kb HpaI-BglII gE fragment. The position of the 2.4-kb gE band is shown on the right, and positions (in kilobases) of DNA size markers are shown on the left. (B) Model of HSV-1 gE, a 550-amino-acid glycoprotein. Sig, predicted signal sequence, amino acids 1 to 23; # # #, the domain on gE, amino acids 235 to 264, that interacts with gI to form a hetero-oligomer complex (3); ∗∗∗, the region of gE, amino acids 235 to 380, which comprises the IgG Fc binding domain (3, 14); •••, the gE domain of homology with mammalian FcγRs. gE amino acids 322 to 359 have 46% identity and 66% similarity with domain 2 of human FcγRII (14). TM refers to the predicted transmembrane domain of gE, amino acids 420 to 444. Arrows at amino acids 339 and 406 indicate the positions of four amino acids (ARAA) inserted within and outside, respectively, the IgG Fc binding domain. HpaI and BglII sites were used to delete gE amino acids 124 to 508. The ICP6::lacZ cassette was cloned into this site to generate the gE null virus. The shaded balloons indicate potential N-linked glycosylation sites at gE amino acids 124 and 243. C’s mark the cysteine positions in the extracellular domain of gE at amino acids 63, 88, 271, 280, 289, 297, 314, 323, and 359.