RT Journal Article SR Electronic T1 Cryo-EM structure of the NLRP3 decamer bound to the cytokine release inhibitory drug CRID3 JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.07.22.453353 DO 10.1101/2021.07.22.453353 A1 Inga V. Hochheiser A1 Michael Pilsl A1 Gregor Hagelueken A1 Jonas Moecking A1 Michael Marleaux A1 Rebecca Brinkschulte A1 Eicke Latz A1 Christoph Engel A1 Matthias Geyer YR 2021 UL http://biorxiv.org/content/early/2021/07/22/2021.07.22.453353.abstract AB NLRP3 is an intracellular sensor protein whose activation by a broad spectrum of exogenous and endogenous stimuli leads to inflammasome formation and pyroptosis. The mechanisms leading to NLRP3 activation and the way how antagonistic small molecules function remain poorly understood. Here we report the cryo-electron microscopy structures of full-length NLRP3 in its native form and complexed with the inhibitor CRID3 (also named MCC950). Inactive, ADP-bound NLRP3 is a decamer composed of homodimers of intertwined LRR domains that assemble back-to-back as pentamers with the NACHT domain located at the apical axis of this spherical structure. Molecular contacts between the concave sites of two opposing LRRs are mediated by an acidic loop extending from an LRR transition segment. Binding of CRID3 significantly stabilizes the NACHT and LRR domains relative to each other, allowing structural resolution of 3.9-4.2 Å. CRID3 binds into a cleft, connecting four subdomains of the NACHT with the transition LRR. Its central sulfonylurea group interacts with the Walker A motif of the NLRP3 nucleotide-binding domain and is sandwiched between two arginines from opposing sites, explaining the specificity of NLRP3 for this chemical entity. With the determination of the binding site of this lead therapeutic, specific targeting of NLRP3 for the treatment of autoinflammatory and autoimmune diseases and rational drug optimization are within reach.Competing Interest StatementM.G. and E.L. are co-founders and consultants of IFM Therapeutics. The other authors declare no competing interests.