SINV E2

E2 is a 423 amino acid (~50 kDa) Type I transmembrane protein. It consists of an N-terminal (1-364, SINV numbering) hydrophilic region, followed by a 26 residue membrane-spanning region (365-390) and a 33 residue (391-423) cytoplasmic endo domain. SINV E2 is glycosylated with two asparagine (N)-linked carbohydrate chains at N-196 and N-318. In addition, certain cysteine residues in the cytoplasmic domain and membrane-spanning region of E2 have been implicated as sites for palmitoylation. During the course of the SINV life cycle the E2 glycoprotein is responsible for cell receptor binding while E1 is involved in the subsequent fusion process with the host cell membrane.