3ije
From Proteopedia
Crystal structure of the complete integrin alhaVbeta3 ectodomain plus an Alpha/beta transmembrane fragment
Structural highlights
FunctionITAV_HUMAN The alpha-V integrins are receptors for vitronectin, cytotactin, fibronectin, fibrinogen, laminin, matrix metalloproteinase-2, osteopontin, osteomodulin, prothrombin, thrombospondin and vWF. They recognize the sequence R-G-D in a wide array of ligands. In case of HIV-1 infection, the interaction with extracellular viral Tat protein seems to enhance angiogenesis in Kaposi's sarcoma lesions. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedWe determined the crystal structure of 1TM-alphaVbeta3, which represents the complete unconstrained ectodomain plus short C-terminal transmembrane stretches of the alphaV and beta3 subunits. 1TM-alphaVbeta3 is more compact and less active in solution when compared with DeltaTM-alphaVbeta3, which lacks the short C-terminal stretches. The structure reveals a bent conformation and defines the alpha-beta interface between IE2 (EGF-like 2) and the thigh domains. Modifying this interface by site-directed mutagenesis leads to robust integrin activation. Fluorescent lifetime imaging microscopy of inactive full-length alphaVbeta3 on live cells yields a donor-membrane acceptor distance, which is consistent with the bent conformation and does not change in the activated integrin. These data are the first direct demonstration of conformational coupling of the integrin leg and head domains, identify the IE2-thigh interface as a critical steric barrier in integrin activation, and suggest that inside-out activation in intact cells may involve conformational changes other than the postulated switch to a genu-linear state. Crystal structure of the complete integrin alphaVbeta3 ectodomain plus an alpha/beta transmembrane fragment.,Xiong JP, Mahalingham B, Alonso JL, Borrelli LA, Rui X, Anand S, Hyman BT, Rysiok T, Muller-Pompalla D, Goodman SL, Arnaout MA J Cell Biol. 2009 Aug 24;186(4):589-600. PMID:19704023[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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