1NTY
Crystal structure of the first DH/PH domain of Trio to 1.7 A
Summary for 1NTY
| Entry DOI | 10.2210/pdb1nty/pdb |
| Descriptor | Triple functional domain protein (2 entities in total) |
| Functional Keywords | dbl, pleckstrin, gef, rho, gtpase, guanine-nucleotide releasing factor, phosphorylation, signaling protein |
| Biological source | Homo sapiens (human) |
| Total number of polymer chains | 1 |
| Total formula weight | 36431.75 |
| Authors | Skowronek, K.R.,Zheng, Y.,Nassar, N. (deposition date: 2003-01-30, release date: 2004-06-29, Last modification date: 2024-02-14) |
| Primary citation | Skowronek, K.R.,Guo, F.,Zheng, Y.,Nassar, N. The C-terminal basic tail of RhoG assists the guanine nucleotide exchange factor trio in binding to phospholipids. J.Biol.Chem., 279:37895-37907, 2004 Cited by PubMed Abstract: The multidomain protein Trio regulates among others neuronal outgrowth and axonal guidance in vertebrates and invertebrates. Trio contains two Dbl-homology/pleckstrin homology (DH/PH) tandem domains that activate several RhoGTPases. Here, we present the x-ray structure of the N-terminal DH/PH, hereafter TrioN, refined to 1.7-A resolution. We show that the relative orientations of the DH and PH domains of TrioN and free Dbs are similar. However, this relative orientation is dissimilar to Dbs in the Dbs/Cdc42 structure. In vitro nucleotide exchange experiments catalyzed by TrioN show that RhoG is approximately 3x more efficiently exchanged than Rac and support the conclusion that RhoG is likely the downstream target of TrioN. Residues 54 and 69, which are not conserved between the two GTPases, are responsible for this specificity. Dot-blot assay reveals that the TrioN-PH domain does not detectably bind phosphatidylinositol 3,4-bisphosphate, PtdIns(3,4)P(2), or other phospholipids. This finding is supported by our three-dimensional structure and affinity binding experiments. Interestingly, the presence of RhoG but not Rac or a C-terminal-truncated RhoG mutant allows TrioN to bind PtdIns(3,4)P(2) with a micromolar affinity constant. We conclude the variable C-terminal basic tail of RhoG specifically assists the recruitment of the TrioN-PH domain to specific membrane-bound phospholipids. Our data suggest a role for the phosphoinositide 3-kinase, PI 3-kinase, in modulating the Trio/RhoG signaling pathway. PubMed: 15199069DOI: 10.1074/jbc.M312677200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
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