Nuclear receptor ligand-binding domains: reduction of helix H12 dynamics to favour crystallization.
Crystallization trials of the human retinoid X receptor alpha ligand-binding domain (RXRalpha LBD) in complex with various ligands have been carried out. Using fluorescence anisotropy, it has been found that when compared with agonists these small-molecule effectors enhance the dynamics of the RXRalpha LBD C-terminal helix H12. In some cases, the mobility of this helix could be dramatically reduced by the addition of a 13-residue co-activator fragment (CoA). In keeping with these observations, crystals have been obtained of the corresponding ternary RXRalpha LBD-ligand-CoA complexes. In contrast, attempts to crystallize complexes with a highly mobile H12 remained unsuccessful. These experimental observations substantiate the previously recognized role of co-regulator fragments in facilitating the crystallization of nuclear receptor LBDs.
Nahoum
Virginie
V
INSERM, U554, 34090 Montpellier, France.
Lipski
Alexandra
A
Quillard
Fabien
F
Guichou
Jean François
JF
Boublik
Yvan
Y
Pérez
Efrèn
E
Germain
Pierre
P
de Lera
Angel R
AR
Bourguet
William
W
D001665:Binding Sites / Q000502:physiology; D003460:Crystallization; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008024:Ligands; D011237:Predictive Value of Tests; D011485:Protein Binding / Q000502:physiology; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism*; D047490:Retinoid X Receptor alpha / Q000737:chemistry / Q000378:metabolism
D005456:Fluorescent Dyes; D008024:Ligands; D018160:Receptors, Cytoplasmic and Nuclear; D047490:Retinoid X Receptor alpha