TRIM5α saturation assay by WT or CA mutants. Cos7 cells incubated with increasing amounts of VSV-G pseudotyped WT or S109A, S149A or S178A-mutated virions were challenged with fixed infectious doses of HIV-1R7-GFP indicator virus. The percentage of replication (GFP positive cells) was quantified by flow cytometry at day 2 post challenge. Values are plotted as the percentage of GFP positive cells as a function of the amount of VSV-G pseudotyped virus used for saturation of TRIM5α proteins. Data presented are representative of two different experiments.