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

ABSTRACT: We report the crystal structures of the ligand-binding domain (LBD) of a rat inositol 1,4,5-trisphosphate receptor (InsP(3)R) in its apo and InsP(3)-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, InsP(3) binding shifts this equilibrium toward the active state.

SUBMITTER: Lin CC 

PROVIDER: S-EPMC3242432 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature