1E10

[2Fe-2S]-Ferredoxin from Halobacterium salinarum


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 60 
  • Conformers Submitted: 20 
  • Selection Criteria: LEAST RESTRAINT VIOLATION, LOWEST ENERGY 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A Two-Alpha-Helix Extra Domain Mediates the Halophilic Character of a Plant-Type Ferredoxin from Halophilic Archaea.

Marg, B.Schweimer, K.Sticht, H.Oesterhelt, D.

(2005) Biochemistry 44: 29

  • DOI: 10.1021/bi0485169
  • Primary Citation of Related Structures:  1E0Z

  • PubMed Abstract: 
  • The [2Fe-2S] ferredoxin (HsFdx) of the halophilic archaeon Halobacterium salinarum exhibits a high degree of sequence conservation with plant-type ferredoxins except for an insertion of 30 amino acids near its N-terminus which is extremely rich in ac ...

    The [2Fe-2S] ferredoxin (HsFdx) of the halophilic archaeon Halobacterium salinarum exhibits a high degree of sequence conservation with plant-type ferredoxins except for an insertion of 30 amino acids near its N-terminus which is extremely rich in acidic amino acids. Unfolding studies reveal that HsFdx has an unfolding temperature of approximately 85 degrees C in 4.3 M NaCl, but of only 50 degrees C in low salinity, revealing its halophilic character. The three-dimensional structure of HsFdx was determined by NMR spectroscopy, resulting in a backbone rmsd of 0.6 A for the diamagnetic regions of the protein. Whereas the overall structure of HsFdx is very similar to that of the plant-type ferredoxins, two additional alpha-helices are found in the acidic extra domain. (15)N NMR relaxation studies indicate that HsFdx is rigid, and the flexibility of residues is similar throughout the molecule. Monitoring protein denaturation by NMR did not reveal differences between the core fold and the acidic domain, suggesting a cooperative unfolding of both parts of the molecule. A mutant of the HsFdx in which the acidic domain is replaced with a short loop of the nonhalophilic Anabaena ferredoxin shows a considerably changed expression pattern. The halophilic wild-type protein is readily expressed in large amounts in H. salinarum, but not in Escherichia coli, whereas the mutant ferredoxin could only be overexpressed in E. coli. The salt concentration was also found to play a critical role for the efficiency of cluster reconstitution: the cluster of HsFdx could be reconstituted only in a solution containing molar concentrations of NaCl, while the reconstitution of the cluster in the mutant protein proceeds efficiently in low salt. These findings suggest that the acidic domain mediates the halophilic character which is reflected in its thermostability, the exclusive expression in H. salinarum, and the ability to efficiently reconstitute the iron-sulfur cluster only at high salt concentrations.


    Related Citations: 
    • Sequence-Specific 1H, 13C and 15N Resonance Assignments and Secondary Structure of [2Fe-2S] Ferredoxin from Halobacterium Salinarum
      Schweimer, K.,Marg, B.-L.,Oesterhelt, D.,Roesch, P.,Sticht, H.
      (2000) J.Biomol.NMR 16: 347


    Organizational Affiliation

    Max-Planck-Institut für Biochemie, Abteilung Membranbiochemie, Am-Klopferspitz 18a, 82152 Martinsried, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
FERREDOXIN
A
128Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1)Gene Names: fdx (fer2)
Find proteins for P00216 (Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1))
Go to UniProtKB:  P00216
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FES
Query on FES

Download SDF File 
Download CCD File 
A
FE2/S2 (INORGANIC) CLUSTER
Fe2 S2
NIXDOXVAJZFRNF-UHFFFAOYSA-N
 Ligand Interaction
ACE
Query on ACE

Download SDF File 
Download CCD File 
A
ACETYL GROUP
C2 H4 O
IKHGUXGNUITLKF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 60 
  • Conformers Submitted: 20 
  • Selection Criteria: LEAST RESTRAINT VIOLATION, LOWEST ENERGY 
  • Olderado: 1E10 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-04-09
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance