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From Proteopedia
STRUCTURE OF RHOGDI: A C-TERMINAL BINDING DOMAIN TARGETS AN N-TERMINAL INHIBITORY PEPTIDE TO GTPASES, NMR, 20 STRUCTURES
Structural highlights
FunctionGDIR1_BOVIN In glioma cells, inhibits cell migration and invasion by mediating the signals of SEMA5A and PLXNB3 that lead to inactivation of RAC1 (By similarity). Regulates the GDP/GTP exchange reaction of the Rho proteins by inhibiting the dissociation of GDP from them, and the subsequent binding of GTP to them.[1] [2] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe Rho GDP-dissociation inhibitors (GDIs) negatively regulate Rho-family GTPases. The inhibitory activity of GDI derives both from an ability to bind the carboxy-terminal isoprene of Rho family members and extract them from membranes, and from inhibition of GTPase cycling between the GTP- and GDP-bound states. Here we demonstrate that these binding and inhibitory functions of rhoGDI can be attributed to two structurally distinct regions of the protein. A carboxy-terminal folded domain of relative molecular mass 16,000 (M[r] 16K) binds strongly to the Rho-family member Cdc42, yet has little effect on the rate of nucleotide dissociation from the GTPase. The solution structure of this domain shows a beta-sandwich motif with a narrow hydrophobic cleft that binds isoprenes, and an exposed surface that interacts with the protein portion of Cdc42. The amino-terminal region of rhoGDI is unstructured in the absence of target and contributes little to binding, but is necessary to inhibit nucleotide dissociation from Cdc42. These results lead to a model of rhoGDI function in which the carboxy-terminal binding domain targets the amino-terminal inhibitory region to GTPases, resulting in membrane extraction and inhibition of nucleotide cycling. C-terminal binding domain of Rho GDP-dissociation inhibitor directs N-terminal inhibitory peptide to GTPases.,Gosser YQ, Nomanbhoy TK, Aghazadeh B, Manor D, Combs C, Cerione RA, Rosen MK Nature. 1997 Jun 19;387(6635):814-9. PMID:9194563[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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