Nuclear receptors bind to coactivators in a ligand-dependent manner.  A common feature of nuclear receptor coactivators is that they contain one or more LXXLL binding motifs (a contiguous sequence of 5 amino acids where L = leucine and X = any amino acid) referred to as NR (nuclear receptor) boxes.  The LXXLL binding motifs have been shown by X-ray crystallography to bind to a groove on the surface of ligand binding domain of nuclear receptors.  Examples include:
* ARA (androgen receptor associated protein)
** ARA54 ()
** ARA55 ()
** ARA70 ()
* AIRE
* BCAS3 (breast carcinoma amplified sequence 3)
* CREB-binding protein
* CRTC (CREB regulated transcription coactivator)
** CRTC1 ()
** CRTC2 ()
** CRTC3 ()
* CARM1 (coactivator-associated arginine methyltransferase 1) 
* Nuclear receptor coactivator (NCOA)
** NCOA1/SRC-1 (steroid receptor coactivator-1)/ 
** NCOA2/GRIP1 (glucocorticoid receptor interacting protein 1)/ TIF2 (transcriptional intermediary factor 2)  
** NCOA3/AIB1 (amplified in breast)  
** NCOA4/ARA70 (androgen receptor associated protein 70)  
** NCOA5 () 
** NCOA6 ()
** NCOA7 ()
* p300 
* PCAF (p300/CBP associating factor) 
* PGC1 (proliferator activated receptor gamma coactivator 1)
** PPARGC1A ()
** PPARGC1B ()
* PNRC (proline-rich nuclear receptor coactivator 1)
** PNRC1 ()
** PNRC2 ()