6HV0 image
Entry Detail
PDB ID:
6HV0
Title:
IRE1 kinase/RNase in complex with imidazo[1,2-b]pyridazin-8-amine compound 33
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2018-10-09
Release Date:
2019-02-27
Method Details:
Experimental Method:
Resolution:
2.73 Å
R-Value Free:
0.26
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Serine/threonine-protein kinase/endoribonuclease IRE1
Chain IDs:A
Chain Length:416
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Binding to an Unusual Inactive Kinase Conformation by Highly Selective Inhibitors of Inositol-Requiring Enzyme 1 alpha Kinase-Endoribonuclease.
J.Med.Chem. 62 2447 2465 (2019)
PMID: 30779566 DOI: 10.1021/acs.jmedchem.8b01721

Abstact

A series of imidazo[1,2- b]pyridazin-8-amine kinase inhibitors were discovered to allosterically inhibit the endoribonuclease function of the dual kinase-endoribonuclease inositol-requiring enzyme 1α (IRE1α), a key component of the unfolded protein response in mammalian cells and a potential drug target in multiple human diseases. Inhibitor optimization gave compounds with high kinome selectivity that prevented endoplasmic reticulum stress-induced IRE1α oligomerization and phosphorylation, and inhibited endoribonuclease activity in human cells. X-ray crystallography showed the inhibitors to bind to a previously unreported and unusually disordered conformation of the IRE1α kinase domain that would be incompatible with back-to-back dimerization of the IRE1α protein and activation of the endoribonuclease function. These findings increase the repertoire of known IRE1α protein conformations and can guide the discovery of highly selective ligands for the IRE1α kinase site that allosterically inhibit the endoribonuclease.

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Primary Citation of related structures