3LAW

Structure of GTP-bound L129F mutant Rab7


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.220 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Disease mutations in Rab7 result in unregulated nucleotide exchange and inappropriate activation.

McCray, B.A.Skordalakes, E.Taylor, J.P.

(2010) Hum.Mol.Genet. 19: 1033-1047

  • DOI: 10.1093/hmg/ddp567

  • PubMed Abstract: 
  • Rab GTPases are molecular switches that orchestrate vesicular trafficking, maturation and fusion by cycling between an active, GTP-bound form, and an inactive, GDP-bound form. The activity cycle is coupled to GTP hydrolysis and is tightly controlled ...

    Rab GTPases are molecular switches that orchestrate vesicular trafficking, maturation and fusion by cycling between an active, GTP-bound form, and an inactive, GDP-bound form. The activity cycle is coupled to GTP hydrolysis and is tightly controlled by regulatory proteins. Missense mutations of the GTPase Rab7 cause a dominantly inherited axonal degeneration known as Charcot-Marie-Tooth type 2B through an unknown mechanism. We present the 2.8 A crystal structure of GTP-bound L129F mutant Rab7 which reveals normal conformations of the effector binding regions and catalytic site, but an alteration to the nucleotide binding pocket that is predicted to alter GTP binding. Through extensive biochemical analysis, we demonstrate that disease-associated mutations in Rab7 do not lead to an intrinsic GTPase defect, but permit unregulated nucleotide exchange leading to both excessive activation and hydrolysis-independent inactivation. Consistent with augmented activity, mutant Rab7 shows significantly enhanced interaction with a subset of effector proteins. In addition, dynamic imaging demonstrates that mutant Rab7 is abnormally retained on target membranes. However, we show that the increased activation of mutant Rab7 is counterbalanced by unregulated, GTP hydrolysis-independent membrane cycling. Notably, disease mutations are able to rescue the membrane cycling of a GTPase-deficient mutant. Thus, we demonstrate that disease mutations uncouple Rab7 from the spatial and temporal control normally imposed by regulatory proteins and cause disease not by a gain of novel toxic function, but by misregulation of native Rab7 activity.


    Organizational Affiliation

    Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN 38105-3678, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ras-related protein Rab-7a
A, B, C, D, E
207Homo sapiensMutation(s): 1 
Gene Names: RAB7A (RAB7)
Find proteins for P51149 (Homo sapiens)
Go to Gene View: RAB7A
Go to UniProtKB:  P51149
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

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

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.220 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 35.554α = 71.24
b = 89.335β = 85.97
c = 89.378γ = 85.91
Software Package:
Software NamePurpose
HKL-2000data reduction
PHASERphasing
REFMACrefinement
HKL-2000data collection
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-01-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance