1ux6
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STRUCTURE OF A THROMBOSPONDIN C-TERMINAL FRAGMENT REVEALS A NOVEL CALCIUM CORE IN THE TYPE 3 REPEATS
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 with CA as ligand. Structure known Active Site: AC1. 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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