Synthesis of fused glycoprotein D of herpes simplex virus type 1 but not type 2 inhibits Escherichia coli hosts.

Glycoprotein D from either Herpes simplex virus type 1 (gD-1) or type 2 (gD-2) has been expressed in Escherichia coli as a series of chimeric proteins. The expression vector used in this study, pJS413, was derived from pBR322 and contains several cloning sites between the lacZ promoter-operator and the phage lambda cro gene. Plasmids containing fusions between the cro gene, gD-related sequences and lacZ was constructed and shown to direct the synthesis of 160-kDa proteins. The accumulation of fusion protein could be visualized as inclusion bodies when the cells were examined by dark phase-contrast or transmission electron microscopy. None of the plasmids that encoded cro::gD gene fusions yielded significant amounts of material upon induction with isopropyl-beta-D-thiogalactopyranoside. In addition, certain plasmids produced a form of Cro-gD-1 fusion protein which resulted in severe growth inhibition of E. coli. These inhibitory effects were attributed to the presence of specific gD-1 sequences, i.e., the transmembrane and cytoplasmic anchor region of the protein.