PURIFICATION OF THE HUMAN RAR-GAMMA LIGAND-BINDING DOMAIN AND CRYSTALLIZATION OF ITS COMPLEX WITH ALL-TRANS-RETINOIC ACID

A 28-kDa fragment (residues 178-423) of the human retinoic acid recept or gamma, hRAR gamma D(3)E, encompassing the ligand-binding domain (LB D) was overproduced in Escherichia coli and purified as a monomer to m ore than 95% purity and homogeneity. The K-d for all-trans retinoic ac id binding was 0.6+/-0.1 nM. Crystals of the LED complexed with all-tr ans retinoic acid were grown at pH 7 from sodium acetate in the presen ce of detergents using the vapor diffusion method. They diffract to 2. 0 Angstrom using a synchrotron radiation (lambda=0.91 Angstrom) and be long to the tetragonal space group P4(1)2(1)2 with unit cell parameter s a=b=60.6 Angstrom and c=155.3 Angstrom, one monomer per asymmetric u nit, a solvent content of ca. 33%, and a V-m value of approximate to 2 Angstrom(3)/dalton. (C) 1997 Academic Press