Construction and expression of A3G-3A chimera. (A) Sequence alignment of A3G and A3A. Highlighted areas indicate regions of amino acid identity. Arrows mark the location of unique BamHI and HindIII restriction sites in the expression vectors used for construction of the A3G-3A chimera. The chimera was constructed by replacing the BamHI and HindIII fragment in A3G by that of A3A. (B) Schematic illustration of the APOBEC expression vectors used in this study. (C) Expression of APOBEC proteins. HeLa cells were transfected with 5 μg each of pcDNA-A3A (lane 1), pcDNA-A3G-3A (lane 2), and pcDNA-A3G (lane 3). Total cell lysates were prepared 24 h after transfection and analyzed by immunoblotting for the expression of A3A, A3G-3A, and A3G, respectively using an A3G-specific polyclonal peptide antibody (ApoC17). Proteins are identified on the right.