Fig. 2.

Positively charged amino acids on the virus surface will interact with the highly sulfated uronic acid and glucosamines on cellular HS proteoglycans (HSPGs), probably via HS binding motifs (indicated in the top panel). These interactions can lead to virus entry by (1) the HSPG acting as an attachment receptor only, potentially by increasing the amount of virus particles interacting with the cellular surface, thus increasing the probability of virus interaction with a proteinaceous entry receptor or leading to recruitment of entry receptors to a site of virus binding. (2) HSPGs may also act as both attachment and entry receptors, promoting entry without the recruitment or interactions of any other receptor. Figure generated using BioRender (www.biorender.com).