Attaches the virion to the host cell membrane by interacting with heparan sulfate, initiating the infection (PubMed:3655746, PubMed:10400758, PubMed:10864656). Interacts with host CX3CR1, the receptor for the CX3C chemokine fractalkine, to modulate the immune response and facilitate infection (PubMed:26658574, PubMed:11477410, PubMed:26107373). Unlike the other paramyxovirus attachment proteins, lacks both neuraminidase and hemagglutinating activities (Probable). Helps the virus escape antibody-dependent restriction of replication by acting as an antigen decoy and by modulating the activity of leukocytes bearing Fc-gamma receptors. Homooligomer (PubMed:1634876). Interacts (via N-terminus) with protein M (PubMed:15958665). Part of a complex composed of F1, F2 and G glycoproteins (PubMed:18036342). Interacts with protein SH (PubMed:15659757). Interacts with host heparate sulfate; this interaction probably participates in the viral attachment to the host cell (PubMed:10400758). Interacts with host CX3CR1; this interaction plays an important role in viral entry (PubMed:11477410, PubMed:26658574). Interacts with the host lectins CD209/DC-SIGN and CD209L/L-SIGN on dendritic cells; these interactions stimulate the phosphorylation of MAPK3/ERK1 and MAPK1/ERK2, which inhibits dendritic cell activation and could participate in the limited immunity against RSV reinfection (PubMed:22090124). The protein is shed from infected cells before the appearance of progeny virus (By similarity). The initiation at the downstream methionine removes a portion of the transmembrane domain. The remaining hydrophobic portion of the sG protein is essential for translocating it into the lumen of the ER during translation and would likely maintain its membrane association until a proteolytic event releases the mature sG protein into the medium (By similarity). Contains a linear heparin binding domain essential for virus attachment to the host. Cleaved to give rise to the mature sG protein which lacks the transmembrane domain. N- and O-glycosylated (PubMed:4069997). May carry 30-40 separate O-linked carbohydrate chains distributed among the 91 serine and threonine residues (PubMed:1634876, PubMed:3858865, PubMed:2164608). Palmitoylated. Belongs to the pneumoviruses glycoprotein G family.