2dtg
From Proteopedia
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| , resolution 3.80Å | |||||||
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| Activity: | Receptor protein-tyrosine kinase, with EC number 2.7.10.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Insulin receptor (IR) ectodomain in complex with fab's
Contents |
Overview
The insulin receptor is a phylogenetically ancient tyrosine kinase receptor found in organisms as primitive as cnidarians and insects. In higher organisms it is essential for glucose homeostasis, whereas the closely related insulin-like growth factor receptor (IGF-1R) is involved in normal growth and development. The insulin receptor is expressed in two isoforms, IR-A and IR-B; the former also functions as a high-affinity receptor for IGF-II and is implicated, along with IGF-1R, in malignant transformation. Here we present the crystal structure at 3.8 A resolution of the IR-A ectodomain dimer, complexed with four Fabs from the monoclonal antibodies 83-7 and 83-14 (ref. 4), grown in the presence of a fragment of an insulin mimetic peptide. The structure reveals the domain arrangement in the disulphide-linked ectodomain dimer, showing that the insulin receptor adopts a folded-over conformation that places the ligand-binding regions in juxtaposition. This arrangement is very different from previous models. It shows that the two L1 domains are on opposite sides of the dimer, too far apart to allow insulin to bind both L1 domains simultaneously as previously proposed. Instead, the structure implicates the carboxy-terminal surface of the first fibronectin type III domain as the second binding site involved in high-affinity binding.
Disease
Known diseases associated with this structure: Diabetes mellitus, insulin-resistant, with acanthosis nigricans OMIM:[147670], Hyperinsulinemic hypoglycemia, familial, 5 OMIM:[147670], Leprechaunism OMIM:[147670], Rabson-Mendenhall syndrome OMIM:[147670]
About this Structure
2DTG is a Single protein structure of sequence from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA.
Reference
Structure of the insulin receptor ectodomain reveals a folded-over conformation., McKern NM, Lawrence MC, Streltsov VA, Lou MZ, Adams TE, Lovrecz GO, Elleman TC, Richards KM, Bentley JD, Pilling PA, Hoyne PA, Cartledge KA, Pham TM, Lewis JL, Sankovich SE, Stoichevska V, Da Silva E, Robinson CP, Frenkel MJ, Sparrow LG, Fernley RT, Epa VC, Ward CW, Nature. 2006 Sep 14;443(7108):218-21. Epub 2006 Sep 6. PMID:16957736
Page seeded by OCA on Thu Mar 20 16:31:18 2008
