Structure of Rheb-Y35A mutant in GDP- and GMPPNP-bound forms

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.167 

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This is version 1.3 of the entry. See complete history


An Autoinhibited Noncanonical Mechanism of GTP Hydrolysis by Rheb Maintains mTORC1 Homeostasis.

Mazhab-Jafari, M.T.Marshall, C.B.Ishiyama, N.Ho, J.Di Palma, V.Stambolic, V.Ikura, M.

(2012) Structure 20: 1528-1539

  • DOI: https://doi.org/10.1016/j.str.2012.06.013
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Rheb, an activator of mammalian target of rapamycin (mTOR), displays low intrinsic GTPase activity favoring the biologically activated, GTP-bound state. We identified a Rheb mutation (Y35A) that increases its intrinsic nucleotide hydrolysis activity ∼10-fold, and solved structures of both its active and inactive forms, revealing an unexpected mechanism of GTP hydrolysis involving Asp65 in switch II and Thr38 in switch I. In the wild-type protein this noncanonical mechanism is markedly inhibited by Tyr35, which constrains the active site conformation, restricting the access of the catalytic Asp65 to the nucleotide-binding pocket. Rheb Y35A mimics the enthalpic and entropic changes associated with GTP hydrolysis elicited by the GTPase-activating protein (GAP) TSC2, and is insensitive to further TSC2 stimulation. Overexpression of Rheb Y35A impaired the regulation of mTORC1 signaling by growth factor availability. We demonstrate that the opposing functions of Tyr35 in the intrinsic and GAP-stimulated GTP catalysis are critical for optimal mTORC1 regulation.

  • Organizational Affiliation

    Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
GTP-binding protein Rheb
A, B
167Homo sapiensMutation(s): 1 
Gene Names: RHEBRHEB2
UniProt & NIH Common Fund Data Resources
Find proteins for Q15382 (Homo sapiens)
Explore Q15382 
Go to UniProtKB:  Q15382
PHAROS:  Q15382
GTEx:  ENSG00000106615 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ15382
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.167 
  • Space Group: P 2 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.247α = 90
b = 69.873β = 90
c = 79.195γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
PHENIXmodel building
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-06-20
    Type: Initial release
  • Version 1.1: 2012-08-15
    Changes: Database references
  • Version 1.2: 2012-09-26
    Changes: Database references
  • Version 1.3: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description