Fig. 2: Potential transcriptional regulation role of AHR PAS-B C-ter loop.
From: Structural basis for the ligand-dependent activation of heterodimeric AHR-ARNT complex
a Overall structure of the PAS-B domains of AHR-ARNT heterodimer. The C-ter loop of AHR PAS-B is colored in light pink. b The detailed interactions between the C-ter loop of AHR PAS-B and ARNT. The residues of AHR and ARNT are colored in magenta and green, respectively. These interactions were analyzed by the Ligplus+ program78. c Co-IP experiments showing the effect of C-ter loop deletion on the formation of AHR-ARNT heterodimers in cells. This experiment was performed three times with similar results. d, e XRE reporter assays (d) and qPCR assays (e) evaluating the effects of C-ter loop deletion on AHR transcriptional activity in HEK293 cells. f Enlarged view near the PAS-B dimer interface where H324 of AHR forms hydrogen bonds with A405 and G407 of C-ter loop. g, h XRE reporter assays (g) and qPCR assays (h) evaluating the effects of hAHR H326A mutation (corresponding to H324 in pAHR) on transactivation in HEK293 cells. For the panels d, e, g, h: error bars, mean ± s.d.; n = 3 (biological replicates); statistical significance, ** p < 0.01, *** p < 0.001, **** p < 0.0001 (p-values shown on the charts calculated using unpaired two-tailed t test versus the WT group).
