Core structure of GP2 from Ebola virus. GP2 is the transmembrane-anchored subunit of GP, the viral surface envelope glycoprotein. The glycoprotein is responsible for attaching to and entering host cells. Ebola hemorrhagic fever (Ebola HF) is a severe, often fatal disease in humans and nonhuman primates (monkeys, gorillas, and chimpanzees) that has appeared sporadically since its initial recognition in 1976.