Genomic structure of NCOA3 with NCBI Build 35.1 genomic positions indicated. Black boxes indicate exons. The translational start (*) and stop codons (^) are also shown. UTR, untranslated region.

Structural features of AIB1. AIB1 contains a basic helix-loop-helix preceding a PAS (Per/Arnt/Sim) region, serine-and threonine-rich regions, and a charged cluster. There is also a glutamine-rich region that contains a polyglutamine tract. The central portion of the protein contains three LXXLL motifs (L=leucine, X=any amino acid) that are critical for interaction with ligand-bound nuclear receptors. An activation domain located C-terminal to the nuclear receptor interaction domain contains three LXXLL motifs that are important for interaction with general transcription cointegrators, CREB binding protein (CBP)/p300. A second transcriptional activation domain is responsible for interaction with histone methyltransferases, coactivator-associated arginine methyltranserase 1 (CARM1) and PRMT1.