Peptide inhibition of human cytomegalovirus infection

Melnik, Lilia I; Garry, Robert F; Morris, Cindy A

Structural studies place herpes simplex virus type 1 gB-1 [28] and Epstein-Barr virus gB into class III viral fusion proteins (VFP) [29] , which also includes VSV G [30] , members of the GP64 superfamily (baculovirus and thogotovirus) [31] and tentatively bornavirus G [32] . Because gB is the most highly conserved envelope protein amongst the mammalian and avian herpesvirues [25, 33] , gB of HCMV is likely to be a class III VFP and shares structural features with gB of other members of the Herpesviridae. Class III viral fusion proteins share certain characteristics found in class I or class II viral fusion proteins. The class III viral fusion proteins contain an extended α-helix that trimerizes in the postfusion forms of the proteins [28, 30, 34] , as has been well-documented for the post-fusion forms of the class I viral fusion proteins of orthomyxoviruses, retroviruses, paramyxoviruses, arenaviruses, and coronaviruses [32] . Similarly, the class II viral fusion proteins of flaviviruses and alphaviruses contain a fusion domain comprised principally of β-sheets and "fusion loops." Class III viral fusion proteins also possess a fusion domain, as well as several other features of class II viral fusion proteins, suggesting that these two classes of proteins may share a common progenitor [31] .