  Atomic Force Microscopy was utilized to study the morphology of Gag,
{\Psi}RNA, and their binding complexes with lipids in a solution environment
with 0.1{\AA} vertical and 1nm lateral resolution. TARpolyA RNA was used as a
RNA control. The lipid used was phospha-tidylinositol-(4,5)-bisphosphate
(PI(4,5)P2). The morphology of specific complexes Gag-{\Psi}RNA, Gag-TARpolyA
RNA, Gag-PI(4,5)P2 and PI(4,5)P2-{\Psi}RNA-Gag were studied. They were imaged
on either positively or negatively charged mica substrates depending on the net
charges carried. Gag and its complexes consist of monomers, dimers and
tetramers, which was confirmed by gel electrophoresis. The addition of specific
{\Psi}RNA to Gag is found to increase Gag multimerization. Non-specific
TARpolyA RNA was found not to lead to an increase in Gag multimerization. The
addition PI(4,5)P2 to Gag increases Gag multimerization, but to a lesser extent
than {\Psi}RNA. When both {\Psi}RNA and PI(4,5)P2 are present Gag undergoes
comformational changes and an even higher degree of multimerization.
