Apo and InsP3-bound crystal structures of the ligand-binding domain of an InsP3 receptor

Department of Physiology, Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Nature Structural & Molecular Biology (Impact Factor: 13.31). 09/2011; 18(10):1172-4. DOI: 10.1038/nsmb.2112
Source: PubMed


We report the crystal structures of the ligand-binding domain (LBD) of a rat inositol 1,4,5-trisphosphate (InsP3) receptor (InsP3R) in its apo and InsP3-bound conformations. Comparison of these two conformations reveals that LBD's first β-trefoil fold (β-TF1) and armadillo repeat fold (ARF) move together as a unit relative to its second β-trefoil fold (β-TF2). Whereas apo-LBD may spontaneously transition between gating conformations, InsP3 binding shifts this equilibrium towards the active state.

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Available from: Kyuwon Baek, Apr 27, 2014
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    • "and B) [15] [16]. Other evidence for interactions between the ligand-binding domains and IP 3 -induced conformational changes comes from NMR and small-angle X-ray scattering studies performed when these domains are expressed as independent entities [55]. "
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