Sindbis virus glycoprotein E1 is divided into two discrete domains at amino acid 129 by disulfide bridge connections

The E1 membrane glycoprotein of Sindbis virus contains structural and funct ional domains, which are conformationally dependent on the presence of intr amolecular disulfide bridges (B. A. Abell and D. T. Brown, J. Virol. 67:549 6-5501, 1993; R. P. Anthony, A. M. Paredes, and D. T. Brown, Virology 190:3 30-336, 1992). We have examined the disulfide bonds in E1 and have determin ed that the E1 membrane glycoprotein contains two separate sets of intercon necting disulfide linkages, which divide the protein into two domains at am ino acid 129. These separate sets of disulfides mag stabilize and define th e structural and functional regions of the E1 protein.