1H65

Crystal structure of pea Toc34 - a novel GTPase of the chloroplast protein translocon


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Crystal Structure of Pea Toc34 - a Novel Gtpase of the Chloroplast Protein Translocon

Sun, Y.J.Forouhar, F.Li, H.M.Tu, S.L.Yeh, Y.H.Kao, S.Shr, H.L.Chou, C.C.Chen, C.Hsiao, C.D.

(2002) Nat.Struct.Mol.Biol. 9: 95

  • DOI: 10.1038/nsb744

  • PubMed Abstract: 
  • Toc34, a 34-kDa integral membrane protein, is a member of the Toc (translocon at the outer-envelope membrane of chloroplasts) complex, which associates with precursor proteins during protein transport across the chloroplast outer membrane. Here we re ...

    Toc34, a 34-kDa integral membrane protein, is a member of the Toc (translocon at the outer-envelope membrane of chloroplasts) complex, which associates with precursor proteins during protein transport across the chloroplast outer membrane. Here we report the 2.0 A resolution crystal structure of the cytosolic part of pea Toc34 in complex with GDP and Mg2+. In the crystal, Toc34 molecules exist as dimers with features resembling those found in a small GTPase in complex with a GTPase activating protein (GAP). However, gel filtration experiments revealed that dimeric and monomeric forms of Toc34 coexisted in phosphate saline buffer solution at pH 7.2. Mutation of Arg 128, an essential residue for dimerization, to an Ala residue led to the formation of an exclusively monomeric species whose GTPase activity is significantly reduced compared to that of wild type Toc34. These results, together with a number of structural features unique to Toc34, suggest that each monomer acts as a GAP on the other interacting monomer.


    Related Citations: 
    • Identification of Two GTP-Binding Proteins in the Chloroplast Protein Import Machinery.
      Kessler, F.,Blobel, G.,Patel, H.,Schnell, D.
      (1994) Science 266: 1035


    Organizational Affiliation

    Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, ROC.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CHLOROPLAST OUTER ENVELOPE PROTEIN OEP34
A, B, C
270Pisum sativumMutation(s): 0 
Gene Names: TOC34 (IAP34, OEP34)
EC: 3.6.5.-
Find proteins for Q41009 (Pisum sativum)
Go to UniProtKB:  Q41009
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP

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

Download SDF File 
Download CCD File 
A, B, C
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.186 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 143.160α = 90.00
b = 78.673β = 91.44
c = 67.279γ = 90.00
Software Package:
Software NamePurpose
SOLVEphasing
SCALEPACKdata scaling
DPSdata reduction
CNSrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-01-29
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2019-02-27
    Type: Data collection, Derived calculations, Experimental preparation, Other
  • Version 1.4: 2019-06-12
    Type: Data collection, Database references, Structure summary