Figure 5
Schematic diagrams of two alternate hypothetical models for molecular action of STR of different length.
In Model 1, transcriptional factor (TF) binds directly to the repeat motifs of STR. Therefore, the longer allele of the STR allows the binding of more TF and thus results in higher (or lower if that TF is inhibitory) transactivation activity. In Model 2, one or more TF(s) bind outside the STR. The steric interaction between TFs bind to both ends of the repeat motif provide the basis of differential transactivation activity between different STR alleles.
