The co-precipitation of Tat with SET-domain containing proteins. A) Biotin-labeled wild type Tat (Lane 3) and acetylated (residues 50 and 51) Tat (Lane 4) peptide immunoprecipitated complexes were probed for the presence of SETDB1, SETDB2, and SUV39H1. 1/20 of input was used as positive control for western blots. B) Biotin-labeled wild type Tat (Lane 2) and acetylated Tat (Lane 3) peptide complexes were probed for the presence of bound G9a and SETMAR. C) Positive control reaction using BRG1 pulldown for the acetylated Tat , and competition experiment with Tat 42–51 peptide (1:10 ratio) as well as purified wild type Tat 1–86 (1:10 ratio) to compete out SETDB1 binding. D) GST-bound wild type Tat and wild type Tax protein complexes were probed for the presence of bound SETDB1 and SETDB2. E) A summary of the Tat binding interactions between all members of the SUV39 family as predicted by SMART) . Under both the Unmodified Tat and Acetylated Tat binding affinity column, a "-" indicates that the enzyme does not bind to the indicated form of Tat, while increasing amounts of "+" indicates that the enzyme bound to the indicated form of Tat with a greater specificity. The "UN" indicates that binding affinities were undetermined.