Location of the spike glycoproteins in the Semliki Forest virus membrane.

Labeling experiments with formyl-[(35)S]-methionyl sulfone methylphosphate and crosslinking studies with dimethylsuberimidate suggest that the spike glycoproteins of Semliki Forest virus extend through the viral membrane into close contact with the nucleocapsid. Based on this finding, we present a mechanism for the formation of virus-specific patches in the host cell plasma membrane during virus assembly.