Initiates virion attachment to host B-lymphocyte cell, leading to virus entry. Acts by binding to host CR2 at the surface of B-lymphocytes, facilitating the binding of viral glycoprotein gp42 to HLA class II molecules. Attachment triggers virion-host membrane fusion and invasion of the host cell. Interacts with host CR2. Most abundant component of the viral envelope. Extensively glycosylated. Primary surface antigen capable of inducing and reacting with virus-neutralizing antibodies. Almost all EBV candidate vaccines are based on gp350 proteins. Belongs to the Epstein-Barr GP350 family.