Figure 2.

Human mtTFA binds to DNA as a dimer. (A) Heterogeneous subunit assay with mtTFA and GST-mtTFA was performed using 2 M mtTFA (lane 2), 2 M GST-mtTFA (lane 3), or both 1 M mtTFA and 1 M GST-mtTFA mixed together (lane 4), incubated with and loaded together with 1 M 30 bp unlabeled LSP DNA fragment (lanes 1 to 4). Arrows indicate the protein DNA complexes that form for mtTFA, GST-mtTFA, or the mixture. The appearance of three bands in lane 4 indicates that the binding species is a dimer of h-mtTFA, as illustrated in panel B. (B) The red and grey circles represent GST-mtTFA and mtTFA with the possible products of their assembly into dimers, trimers or tetramer forms.