Envelope protein which probably plays a role in virus entry into the host cell. Is probably involved in the virus attachment to the host cell surface and associates with the entry/fusion complex (EFC). Needed for fusion and penetration of the virus core into host cell (By similarity). Interacts with G4; this interaction involves formation of a transient disulfide-bonded intermediate, allowing disulfide bond transfer. Localizes to the membrane surrounding the core of mature virus particles (MV). Expressed in the late phase of the viral replicative cycle. Myristoylated. Belongs to the chordopoxvirinae L1 family.