4U5X

Structure of plant small GTPase OsRac1 complexed with the non-hydrolyzable GTP analog GMPPNP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.159 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

The Crystal Structure of the Plant Small GTPase OsRac1 Reveals Its Mode of Binding to NADPH Oxidase

Kosami, K.Ohki, I.Nagano, M.Furuita, K.Sugiki, T.Kawano, Y.Kawasaki, T.Fujiwara, T.Nakagawa, A.Shimamoto, K.Kojima, C.

(2014) J Biol Chem 289: 28569-28578

  • DOI: https://doi.org/10.1074/jbc.M114.603282
  • Primary Citation of Related Structures:  
    4U5X

  • PubMed Abstract: 

    Rac/Rop proteins are Rho-type small GTPases that act as molecular switches in plants. Recent studies have identified these proteins as key components in many major plant signaling pathways, such as innate immunity, pollen tube growth, and root hair formation. In rice, the Rac/Rop protein OsRac1 plays an important role in regulating the production of reactive oxygen species (ROS) by the NADPH oxidase OsRbohB during innate immunity. However, the molecular mechanism by which OsRac1 regulates OsRbohB remains unknown. Here, we report the crystal structure of OsRac1 complexed with the non-hydrolyzable GTP analog guanosine 5'-(β,γ-imido)triphosphate at 1.9 Å resolution; this represents the first active-form structure of a plant small GTPase. To elucidate the ROS production in rice cells, structural information was used to design OsRac1 mutants that displayed reduced binding to OsRbohB. Only mutations in the OsRac1 Switch I region showed attenuated interactions with OsRbohB in vitro. In particular, Tyr(39) and Asp(45) substitutions suppressed ROS production in rice cells, indicating that these residues are critical for interaction with and activation of OsRbohB. Structural comparison of active-form OsRac1 with AtRop9 in its GDP-bound inactive form showed a large conformational difference in the vicinity of these residues. Our results provide new insights into the molecular mechanism of the immune response through OsRac1 and the various cellular responses associated with plant Rac/Rop proteins.


  • Organizational Affiliation

    From the Institute for Protein Research, Osaka University, Suita, Osaka 565-0871.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Rac-like GTP-binding protein 1178Oryza sativa Japonica GroupMutation(s): 2 
Gene Names: RAC1Os01g0229400LOC_Os01g12900
UniProt
Find proteins for Q9SSX0 (Oryza sativa subsp. japonica)
Explore Q9SSX0 
Go to UniProtKB:  Q9SSX0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9SSX0
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.159 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.755α = 90
b = 59.087β = 90
c = 64.393γ = 90
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-08-20
    Type: Initial release
  • Version 1.1: 2014-10-22
    Changes: Database references
  • Version 1.2: 2020-01-29
    Changes: Data collection, Database references, Derived calculations, Other, Source and taxonomy, Structure summary
  • Version 1.3: 2023-11-08
    Changes: Data collection, Database references, Derived calculations, Refinement description