1by4
From Proteopedia
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STRUCTURE AND MECHANISM OF THE HOMODIMERIC ASSEMBLY OF THE RXR ON DNA
Overview
The 9-cis retinoic acid receptor, RXR, binds DNA effectively as a, homodimer or as a heterodimer with other nuclear receptors. The, DNA-binding sites for these RXR complexes are direct repeats of a, consensus sequence separated by one to five base-pairs of intervening, space. Here, we report the 2.1 A crystal structure of the RXR-DNA-binding, domain as a homodimer in complex with its idealized direct repeat DNA, target. The structure shows how a gene-regulatory site can induce, conformational changes in a transcription factor that promote, homo-cooperative assembly. Specifically, an alpha-helix in the T-box is, disrupted to allow efficient DNA-binding and subunit dimerization. RXR, displays a relaxed mode of sequence recognition, interacting with only, three base-pairs in each hexameric half-site. The structure illustrates, how site selection is achieved in this large eukaryotic transcription, factor family through discrete protein-protein interactions and the use of, tandem DNA binding sites with characteristic spacings.
About this Structure
1BY4 is a Single protein structure of sequence from Homo sapiens with ZN as ligand. Full crystallographic information is available from OCA.
Reference
Structural basis of RXR-DNA interactions., Zhao Q, Chasse SA, Devarakonda S, Sierk ML, Ahvazi B, Rastinejad F, J Mol Biol. 2000 Feb 18;296(2):509-20. PMID:10669605
Page seeded by OCA on Mon Nov 12 16:15:23 2007
