The 9aaTAD Is Exclusive Activation Domain in Gal4
The LexA-Gal4 hybrid constructs with activation domains AD-III, 9aaTAD and their artificial variants were assayed in L40 strain for activation of transcription. Gal4 DBD is Gal4 DNA binding domain. The red marks part of the artificial activation domain 9aaTAD (1/2 9aaTAD) and the blue marks part of the natural activation domain 9aaTAD (1/2 9aaTAD). Both these parts generated strong activators in the fusion with the Gal4 DNA binding domain, Gal4 DBD (83–100 aa), which served as other part of the artificial activation domain 9aaTAD (the second 1/2 9aaTAD). The artefact explained previous cloning errors of the reported construct pRJR200 with activation domain AD-III . The impact of proximal amino acids on the function of the activation domain 9aaTAD was tested. The related constructs with and without activation domains AD-III and 9aaTAD are shown again to overview their activities (G81, G49, G59, G42, G405). The average value of the β-galactosidase activities from three independent experiments is presented as a percentage of the reference with standard deviation (means and plusmn; SD; n = 3). We standardized all results to previously reported Gal4 construct HaY including merely the activation domain 9aaTAD with the activity set to 100% . The regions of Gal4 protein in the constructs are noted and graphically presented. The artificial activation domain AD-II is not more shown in this figure. The protein sequences are partially given by amino acid single letter code. Single dot means end of protein sequence, tree points mean continuing of the sequence, which is not more shown.