Structural evidence for a common intermediate in small G protein-GEF reactions
| Autor: | Inka Fricke, Antje Berken, Andrea Scrima, Christoph Thomas, Alfred Wittinghofer |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
GTPase-activating protein
G protein Stereochemistry Arabidopsis Small G Protein Biology Crystallography X-Ray Guanosine Diphosphate Catalysis Protein Structure Secondary GTP-binding protein regulators GTP-Binding Proteins Guanine Nucleotide Exchange Factors Nucleotide Ternary complex Molecular Biology Monomeric GTP-Binding Proteins chemistry.chemical_classification Arabidopsis Proteins Cell Biology Protein Structure Tertiary chemistry Biochemistry Mutant Proteins Guanine nucleotide exchange factor Signal transduction Rho Guanine Nucleotide Exchange Factors Protein Binding |
| Zdroj: | Molecular cell. 25(1) |
| ISSN: | 1097-2765 |
| Popis: | Rho of plants (Rop) proteins belong to the superfamily of small GTP-binding (G) proteins and are vital regulators of signal transduction in plants. In order to become activated, Rop proteins need to exchange GDP for GTP, an intrinsically slow process catalyzed by guanine nucleotide exchange factors (GEFs). RopGEFs show no homology to animal RhoGEFs, and the catalytic mechanism remains elusive. GEF-catalysed nucleotide exchange proceeds via transient ternary and stable binary complexes. While a number of structural studies have analyzed binary nucleotide-free G protein-GEF complexes, very little is known about the ternary complexes. Here we report the X-ray structure of the catalytic PRONE domain of RopGEF8 from Arabidopsis thaliana, both alone and in a ternary complex with Rop4 and GDP. The features of the latter complex, a transient intermediate of the exchange reaction never directly observed before, suggest a common mechanism of catalyzed nucleotide exchange applicable to small G proteins in general. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|