Distinct Gag interaction properties of HIV-1 RNA 5′ leader conformers reveal a mechanism for dimeric genome selection

The distinct Gag interaction properties of 5′L_P and 5′L_T reveal a mechanism for dimeric genome selection. Conformational changes at 5′L affect the Gag interaction. Gag binds to 5′L_P quickly and dissociates from it slowly. The Gag–5′L_P complex is more stable in the presence of competitive agents. The favorable binding properties of 5′L_P may allow sufficient time for Gag to assemble and facilitate HIV-1 assembly. In contrast, Gag binds to 5′L_T slowly but dissociates from it quickly. The Gag–5′L_T complex is also less stable, which may not favor efficient packaging.