FIG. 6.

Positions of the thumb subdomain mutations in RT and their effects on RT stability. (A) High-resolution structure of HIV-1 RT heterodimer (8) with the p66 subunit in tan and the p51 subunit in gray. The thumb subdomain of both subunits is shown in green. (B) Close-up view of the isolated thumb subdomain from p66. In both panels, mutations that cause the most severe degradation phenotype (little or no intact p66 and p51) are shown in pink; these mutations are likely to destabilize the hydrophobic core that is responsible for the folding of thumb subdomains. Mutations for which there is either no effect on RT stability or a modest effect on RT stability (significant amounts of p66 and p51 remaining in the virion) are shown in blue.