The membrane-binding domain of the Rous sarcoma virus Gag protein.

The Gag protein of Rous sarcoma virus (RSV) can direct particle assembly and budding at the plasma membrane independently of the other virus-encoded products. A previous deletion analysis has suggested that the first 86 amino acids of RSV Gag constitute a large membrane-binding domain that is absolutely required for these processes. To test this hypothesis, we inserted these residues in place of the N-terminal membrane-binding domain of the pp60v-src, a transforming protein whose biological activity requires plasma membrane localization. The ability of the Src chimera to induce cellular transformation suggests that the RSV sequence indeed contains an independent, functional domain.