5l7d

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Structure of human Smoothened in complex with cholesterolStructure of human Smoothened in complex with cholesterol

Structural highlights

5l7d is a 2 chain structure with sequence from Escherichia coli and Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 3.2Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

C562_ECOLX Electron-transport protein of unknown function.SMO_HUMAN G protein-coupled receptor that probably associates with the patched protein (PTCH) to transduce the hedgehog's proteins signal. Binding of sonic hedgehog (SHH) to its receptor patched is thought to prevent normal inhibition by patched of smoothened (SMO). Required for the accumulation of KIF7 and GLI3 in the cilia.[1]

Publication Abstract from PubMed

Developmental signals of the Hedgehog (Hh) and Wnt families are transduced across the membrane by Frizzledclass G-protein-coupled receptors (GPCRs) composed of both a heptahelical transmembrane domain (TMD) and an extracellular cysteine-rich domain (CRD). How the large extracellular domains of GPCRs regulate signalling by the TMD is unknown. We present crystal structures of the Hh signal transducer and oncoprotein Smoothened, a GPCR that contains two distinct ligand-binding sites: one in its TMD and one in the CRD. The CRD is stacked a top the TMD, separated by an intervening wedge-like linker domain. Structure-guided mutations show that the interface between the CRD, linker domain and TMD stabilizes the inactive state of Smoothened. Unexpectedly, we find a cholesterol molecule bound to Smoothened in the CRD binding site. Mutations predicted to prevent cholesterol binding impair the ability of Smoothened to transmit native Hh signals. Binding of a clinically used antagonist, vismodegib, to the TMD induces a conformational change that is propagated to the CRD, resulting in loss of cholesterol from the CRD-linker domain-TMD interface. Our results clarify the structural mechanism by which the activity of a GPCR is controlled by ligand-regulated interactions between its extracellular and transmembrane domains.

Structural basis of Smoothened regulation by its extracellular domains.,Byrne EF, Sircar R, Miller PS, Hedger G, Luchetti G, Nachtergaele S, Tully MD, Mydock-McGrane L, Covey DF, Rambo RP, Sansom MS, Newstead S, Rohatgi R Nature. 2016 Jul 28;535(7613):517-22. PMID:27437577[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. Endoh-Yamagami S, Evangelista M, Wilson D, Wen X, Theunissen JW, Phamluong K, Davis M, Scales SJ, Solloway MJ, de Sauvage FJ, Peterson AS. The mammalian Cos2 homolog Kif7 plays an essential role in modulating Hh signal transduction during development. Curr Biol. 2009 Aug 11;19(15):1320-6. doi: 10.1016/j.cub.2009.06.046. Epub 2009, Jul 9. PMID:19592253 doi:http://dx.doi.org/10.1016/j.cub.2009.06.046
  2. Byrne EF, Sircar R, Miller PS, Hedger G, Luchetti G, Nachtergaele S, Tully MD, Mydock-McGrane L, Covey DF, Rambo RP, Sansom MS, Newstead S, Rohatgi R. Structural basis of Smoothened regulation by its extracellular domains. Nature. 2016 Jul 28;535(7613):517-22. PMID:27437577 doi:http://dx.doi.org/10.1038/nature18934

5l7d, resolution 3.20Å

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