2a66
Human Liver Receptor Homologue DNA-Binding Domain (hLRH-1 DBD) in Complex with dsDNA from the hCYP7A1 Promoter
OverviewOverview
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.
About this StructureAbout this Structure
2A66 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the human LRH-1 DBD-DNA complex reveals Ftz-F1 domain positioning is required for receptor activity., Solomon IH, Hager JM, Safi R, McDonnell DP, Redinbo MR, Ortlund EA, J Mol Biol. 2005 Dec 16;354(5):1091-102. Epub 2005 Oct 27. PMID:16289203 Page seeded by OCA on Sat May 3 18:39:28 2008