HIV type 2 Vpx interaction with Gag and incorporation into virus-like particles

The domain of HIV-2 Vpx previously shown to be important for virion incorporation has been mapped to residues 73--89. Mutational analysis of this domain was employed to further define the sequences important for incorporation into virus-like particles, using a vaccinia virus expression system. Deletion of residues 73--89 did not abrogate Vpx packaging, but substitution with alanines markedly reduced incorporation into virus-like particles. Moreover, alanine substitution also disrupted Vpx interaction with Gag, as demonstrated with glutathione S-transferase fusion proteins and the yeast two-hybrid system.