2wbl | pdb_00002wbl
Three-dimensional structure of a binary ROP-PRONE complex
Structural highlights
FunctionROGF8_ARATH Guanine-nucleotide exchange factor (GEF) that acts as an activator of Rop (Rho of plants) GTPases by promoting the exchange of GDP for GTP. Active as homodimer.[1] 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 PubMedAbstract Guanine nucleotide exchange factors (GEFs) catalyze the activation of GTP-binding proteins (G proteins) in a multi-step reaction comprising intermediary complexes with and without nucleotide. Rho proteins of plants (ROPs) are activated by novel RopGEFs with a catalytic PRONE domain. We have previously characterized structures of GDP-bound ROP and a ternary complex between PRONE and ROP including loosely bound GDP. Now, we complete the molecular snapshots of the RopGEF reaction with the nucleotide-free ROP-PRONE structure at 2.9 A. The binary complex surprisingly closely resembles the preceding ternary intermediate including an unusually intact P-loop in the G protein. A striking difference is the prominent contact of the invariant P-loop lysine to a conserved switch II glutamate in ROP, favoring a key role of this interaction in driving out the nucleotide. The nucleotide-free state is supported by additional interactions involving the essential WW-motif in PRONE. We propose that this GEF region stabilizes the intact P-loop conformation, which facilitates re-association with a new nucleotide and further promotes the overall exchange reaction. With our novel structure we provide further insights into the nucleotide exchange mechanism and present a first example of the complete GEF reaction at a molecular level. 3D structure of a binary ROP-PRONE complex: the final intermediate for a complete set of molecular snapshots of the RopGEF reaction.,Thomas C, Fricke I, Weyand M, Berken A Biol Chem. 2009 Mar 31. PMID:19335195[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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