NFkappaB selectivity of estrogen receptor ligands revealed by comparative crystallographic analyses.
Our understanding of how steroid hormones regulate physiological functions has been significantly advanced by structural biology approaches. However, progress has been hampered by misfolding of the ligand binding domains in heterologous expression systems and by conformational flexibility that interferes with crystallization. Here, we show that protein folding problems that are common to steroid hormone receptors are circumvented by mutations that stabilize well-characterized conformations of the receptor. We use this approach to present the structure of an apo steroid receptor that reveals a ligand-accessible channel allowing soaking of preformed crystals. Furthermore, crystallization of different pharmacological classes of compounds allowed us to define the structural basis of NFkappaB-selective signaling through the estrogen receptor, thus revealing a unique conformation of the receptor that allows selective suppression of inflammatory gene expression. The ability to crystallize many receptor-ligand complexes with distinct pharmacophores allows one to define structural features of signaling specificity that would not be apparent in a single structure.
Nettles
Kendall W
KW
Department of Cancer Biology, The Scripps Research Institute, 5353 Parkside Drive, Jupiter, Florida 33458, USA. knettles@scripps.edu
Bruning
John B
JB
Gil
German
G
Nowak
Jason
J
Sharma
Sanjay K
SK
Hahm
Johnnie B
JB
Kulp
Kristen
K
Hochberg
Richard B
RB
Zhou
Haibing
H
Katzenellenbogen
John A
JA
Katzenellenbogen
Benita S
BS
Kim
Younchang
Y
Joachmiak
Andrzej
A
Greene
Geoffrey L
GL
D001665:Binding Sites; D001643:Bridged Bicyclo Compounds / Q000737:chemistry* / Q000494:pharmacology; D018360:Crystallography, X-Ray; D006801:Humans; D006860:Hydrogen Bonding; D008024:Ligands; D008958:Models, Molecular; D009154:Mutation; D016328:NF-kappa B / Q000737:chemistry* / Q000187:drug effects; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011720:Pyrazoles / Q000737:chemistry* / Q000494:pharmacology; D011743:Pyrimidines / Q000737:chemistry* / Q000494:pharmacology; D011960:Receptors, Estrogen / Q000819:agonists / Q000737:chemistry*; D012680:Sensitivity and Specificity; D015398:Signal Transduction; D013329:Structure-Activity Relationship
D001643:Bridged Bicyclo Compounds; D008024:Ligands; D016328:NF-kappa B; D011720:Pyrazoles; D011743:Pyrimidines; D011960:Receptors, Estrogen