Plays a role in virus entry by participating in host receptor binding at the cell surface. Interacts with isoform gQ1. Associates with the glycoprotein complex gH-gL (PubMed:15254169). The gH/gL/gQ1/gQ2 complex binds to human receptor CD46 (PubMed:24215487). Glycosylated by host. This chain is predicted but has not been detected in HHV-6A-infected cells and virion.