The TAL effector AvrBs3 from Xanthomonas campestris pv. vesicatoria is translocated via the type III secretion system into the cytoplasm of the plant cell and localizes to the plant cell nucleus. There, AvrBs3 binds to the UPA-EBE (effector binding element) in the promoter of UPA-genes and activates their transcription. The objective of this work was a detailed analysis of the C-terminal region of AvrBs3. It was known that nuclear localization signals (NLSs) and the activation domain (AD) in the C-terminal region of AvrBs3, contribute to both, the virulence and avirulence function. Here, the AR (adjacent to repeats) region was studied in more detail using mutation analyses. Another goal was the analysis of the mechanism of gene induction by AvrBs3. For this, interactors of the C-terminal region of AvrBs3 were identified, using an altered experimental approach to screen a pepper cDNA library in yeast.