1ux6
STRUCTURE OF A THROMBOSPONDIN C-TERMINAL FRAGMENT REVEALS A NOVEL CALCIUM CORE IN THE TYPE 3 REPEATS
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| , resolution 1.90Å | |||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
Thrombospondins (TSPs) are extracellular regulators of cell-matrix interactions and cell phenotype. The most highly conserved region of all TSPs are the calcium-binding type 3 (T3) repeats and the C-terminal globular domain (CTD). The crystal structure of a cell-binding TSP-1 fragment, spanning three T3 repeats and the CTD, reveals a compact assembly. The T3 repeats lack secondary structure and are organised around a core of calcium ions; two DxDxDGxxDxxD motifs per repeat each encapsulate two calcium ions in a novel arrangement. The CTD forms a lectin-like beta-sandwich and contains four strictly conserved calcium-binding sites. Disruption of the hairpin structure of T3 repeats 6 and 7 decreases protein secretion and stability. The availability for cell attachment of an RGD motif in T3 repeat 7 is modulated by calcium loading. The central architectural role of calcium explains how it is critical for the functions of the TSP C-terminal region. Mutations in the T3 repeats of TSP-5/COMP, which cause two human skeletal disorders, are predicted to disrupt the tertiary structure of the T3-CTD assembly.
About this StructureAbout this Structure
1UX6 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Structure of a thrombospondin C-terminal fragment reveals a novel calcium core in the type 3 repeats., Kvansakul M, Adams JC, Hohenester E, EMBO J. 2004 Mar 24;23(6):1223-33. Epub 2004 Mar 11. PMID:15014436
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