FIG. 1.

HSV-1 recombinants encoding altered forms of ICP27. Shown is a schematic diagram of the ICP27 polypeptide and the approximate positions of the NES, N-terminal acidic region, NLS, RGG box and C-terminal region. The positions of 16 XhoI sites engineered in a family of mutant ICP27 plasmids (43) are indicated. Mutants M11, M15, and M16 contain one or two altered amino acids as a consequence of the engineered XhoI sites at positions 11, 15, and 16, respectively. The sites were also used to construct the in-frame deletion mutants shown. The portion of the ICP27 polypeptide that is encoded in each mutant virus is shown by the horizontal lines. The growth characteristics of each mutant virus in Vero cells are indicated by their ability to form plaques and their virus yield relative to the yield of the wild-type (WT) virus. The ability of the ICP27 mutants to carry out the transrepression function of ICP27, as defined by transient transfection assays using reporter genes, is indicated. ND, not determined.