Cartoon representations of the orientation of LXXLL motifs found in 2 different classes. (A) The orientation of LXXLL motifs of coactivators on the ligand-binding domain of nuclear receptors (NRs). (B-D) The binding orientation of LXXLL motifs of transcription factors: (B) STAT6 binding the PAS-B domain of NcoA-1, (C) cMyb binding the KIX domain of CBP, (D) HEB binding the eTAFH domain of AML1-ETO. The glutamic acids of STAT6 and HEB and the arginine of cMyb providing side chain interactions are in light gray and labeled.