Structure-Based Mutations in the Herpes Simplex Virus 1 Glycoprotein B Ectodomain Arm Impart a Slow-Entry Phenotype

Fan, Qing; Kopp, Sarah J.; Connolly, Sarah A.; Longnecker, Richard

HSV-1 gB and gC bind to cell surface HS proteoglycans, and viruses with these glycoproteins deleted are impaired in the ability to attach to cells (21, 26) . HS binding was mapped to a lysine-rich region of gB (residues 68 to 76) (38) . Mutation of this lysine-rich region disrupts HS binding, and the mutant virus is impaired but remains infectious, indicating that gB binding to HS is not essential for infection (38) . The gB 3A mutations are distant from the HS binding site, so these mutations were not expected to affect HS binding. When cell binding was examined by using a washout assay, the gB 3A and WT viruses demonstrated similar degrees of retention on the cell (Fig. 6) , suggesting that the gB 3A mutations did not impact cell binding.