Purity > 90% as determined by SDS-PAGE. MW: 68.5kDa. Partial: 1-493aa. N-terminal 6xHis-SUMO-tagged. Epstein-Barr virus (strain B95-8) (HHV-4) (Human herpesvirus 4). 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.