Attaches the virion to the host cell membrane by interacting with heparan sulfate, initiating the infection. Interacts with host CX3CR1, the receptor for the CX3C chemokine fractalkine, to modulate the immune response and facilitate infection. Unlike the other paramyxovirus attachment proteins, lacks both neuraminidase and hemagglutinating activities (By similarity). Secreted glycoprotein G helps RSV escape antibody-dependent restriction of replication by acting as an antigen decoy and by modulating the activity of leukocytes bearing Fcgamma receptors. Homooligomer. Interacts (via N-terminus) with protein M. Interacts with protein F; this interaction occurs on the surface of infected cells. Interacts with protein SH. Interacts with host CX3CR1; this interaction modulates host immune response (By similarity). Contains a linear heparin binding domain essential for virus attachment to the host. May carry a lot of separate O-linked carbohydrate chains distributed among serine and threonine residues. Palmitoylated. Belongs to the pneumoviruses glycoprotein G family.