Abstract
The DNA-binding and ligand-binding functions of nuclear receptors are localized to independent domains separated by a flexible hinge. The DNA-binding domain (DBD) of the human liver receptor homologue-1 (hLRH-1), which controls genes central to development and metabolic homeostasis, interacts with monomeric DNA response elements and contains an Ftz-F1 motif that is unique to the NR5A nuclear receptor subfamily. Here, we present the 2.2A resolution crystal structure of the hLRH-1 DBD in complex with duplex DNA, and elucidate the sequence-specific DNA contacts essential for the ability of LRH-1 to bind to DNA as a monomer. We show that the unique Ftz-F1 domain folds into a novel helix that packs against the DBD but does not contact DNA. Mutations expected to disrupt the positioning of the Ftz-F1 helix do not eliminate DNA binding but reduce the transcriptional activity of full-length LRH-1 significantly. Moreover, we find that altering the Ftz-F1 helix positioning eliminates the enhancement of LRH-1-mediated transcription by the coactivator GRIP1, an action that is associated primarily with the distantly located ligand-binding domain (LBD). Taken together, these results indicate that subtle structural changes in a nuclear receptor DBD can exert long-range functional effects on the LBD of a receptor, and significantly impact transcriptional regulation.
Publication types
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Comparative Study
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Alanine / metabolism
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Amino Acid Motifs
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Amino Acid Sequence
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Amino Acid Substitution
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Arginine / chemistry
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Base Sequence
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Binding Sites
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Carrier Proteins / metabolism
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Crystallography, X-Ray*
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DNA / chemistry*
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DNA / metabolism*
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DNA-Binding Proteins / chemistry*
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / isolation & purification
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DNA-Binding Proteins / metabolism*
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Fluorescence Polarization
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Fushi Tarazu Transcription Factors / chemistry*
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Fushi Tarazu Transcription Factors / genetics
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Fushi Tarazu Transcription Factors / metabolism
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Genes, Reporter
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Glutamic Acid / metabolism
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Glycine / chemistry
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Glycine / metabolism
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HeLa Cells
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Humans
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Hydrogen Bonding
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Ligands
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Luciferases / metabolism
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Models, Chemical
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Models, Molecular
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Molecular Sequence Data
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Nerve Tissue Proteins / metabolism
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Oxygen / chemistry
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Promoter Regions, Genetic
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Protein Binding
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Protein Conformation
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Protein Structure, Tertiary
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Receptors, Cytoplasmic and Nuclear / chemistry*
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Receptors, Cytoplasmic and Nuclear / genetics
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Receptors, Cytoplasmic and Nuclear / isolation & purification
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Receptors, Cytoplasmic and Nuclear / metabolism*
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Response Elements
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Transcription Factors / chemistry*
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Transcription Factors / genetics
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Transcription Factors / isolation & purification
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Transcription Factors / metabolism*
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Transcription, Genetic
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Water / chemistry
Substances
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Carrier Proteins
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DNA-Binding Proteins
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Fushi Tarazu Transcription Factors
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GRIP1 protein, human
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Ligands
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NR5A2 protein, human
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Nerve Tissue Proteins
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Receptors, Cytoplasmic and Nuclear
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Transcription Factors
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Water
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Glutamic Acid
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DNA
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Arginine
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Luciferases
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Alanine
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Oxygen
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Glycine