3SEA

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.162 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

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: 10.1016/j.str.2012.06.013

  • 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 ...

    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.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GTP-binding protein Rheb
A, B
167Homo sapiensMutation(s): 1 
Gene Names: RHEB (RHEB2)
Find proteins for Q15382 (Homo sapiens)
Go to Gene View: RHEB
Go to UniProtKB:  Q15382
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP

Download SDF File 
Download CCD File 
A
GUANOSINE-5'-DIPHOSPHATE
C10 H15 N5 O11 P2
QGWNDRXFNXRZMB-UUOKFMHZSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
GNP
Query on GNP

Download SDF File 
Download CCD File 
B
PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER
C10 H17 N6 O13 P3
UQABYHGXWYXDTK-UUOKFMHZSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.162 
  • Space Group: P 2 21 21
Unit Cell:
Length (Å)Angle (°)
a = 57.247α = 90.00
b = 69.873β = 90.00
c = 79.195γ = 90.00
Software Package:
Software NamePurpose
PHENIXphasing
PHENIXrefinement
HKL-2000data scaling
HKL-2000data reduction
PHENIXmodel building
CrystalCleardata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-06-20
    Type: Initial release
  • Version 1.1: 2012-08-15
    Type: Database references
  • Version 1.2: 2012-09-26
    Type: Database references