1FDA

CRYSTAL STRUCTURES OF OXIDIZED AND REDUCED AZOTOBACTER VINELANDII FERREDOXIN AT PH 8 AND PH 6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Work: 0.206 
  • R-Value Observed: 0.206 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structures of oxidized and reduced Azotobacter vinelandii ferredoxin at pH 8 and 6.

Stout, C.D.

(1993) J Biol Chem 268: 25920-25927

  • Primary Citation of Related Structures:  
    1FDA, 1FDB, 5FD1

  • PubMed Abstract: 

    Crystal structures of Azotobacter vinelandii ferredoxin I (FdI) have been solved and refined at 2.2 to 1.9-A resolution at pH 8 and 6 for both the oxidized and dithionite-reduced proteins. Only the [3Fe-4S] cluster is reduced by dithionite. The four structures (denoted FdI8ox, FdI8red, FdI6ox, and FdI6red) have been compared to address three questions: the effect of reduction at pH 8, the effect of pH change on the structure, and the effect of reduction at pH 6. Comparison of the FdI8ox and FdI8red structures shows that Asp-15 changes conformation in a manner consistent with increased anionic repulsion between this residue and the reduced [3Fe-4S]0 cluster. By revealing an electrostatic interaction between Asp-15 and the [3Fe-4S] cluster, this result supports the conclusion in the accompanying paper (Shen, B., Martin, L. L., Butt, J. N., Armstrong, F. A., Stout, C. D., Jensen, G. M., Stephens, P. J., LaMar, G. N., Gorst, C. M., and Burgess, B. K. (1993) J. Biol. Chem. 268, 25928-25939) that Asp-15 participates in protonation of the reduced [3Fe-4S]0 cluster at acid pH. The [3Fe-4S]0 cluster in the FdI8red structure also displays a distinct shift within the protein as well as internal distortions when compared to the [3Fe-4S]+ cluster in the FdI8ox structure. Comparison of the FdI8ox and FdI6ox structures shows that pH change does not have any significant effect on the [3Fe-4S]+ cluster or surrounding residues. Comparison of the FdI6ox and FdI6red structures shows that reduction at pH 6 also does not have any significant effect on the [3Fe-4S] cluster or Asp-15. The absence of structural change supports the conclusion that at acid pH, the reduced [3Fe-4S] cluster is protonated, i.e. [3Fe-4S]0-H+ (Shen et al., 1993). The cluster is not shifted or distorted as in the FdI8red structure. Instead, the [3Fe-4S]o-H+ cluster FdI8red is structurally similar to the [3Fe-4S]+ cluster (FdI8ox, FdI6ox), which has the same net charge. An Asp-15-Lys-84 salt bridge is observed in all four structures, indicating that Asp-15 is ionized at pH 8 and 6. An ionized state for Asp-15 is also implied by a lack of conformational change in Lys-84; the side chain of this residue rearranges when Asp-15 is substituted with a neutral amino acid (Shen et al., 1993).(ABSTRACT TRUNCATED AT 400 WORDS)


  • Organizational Affiliation

    Department of Molecular Biology, Scripps Research Institute, La Jolla, California 92037.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
FERREDOXIN106Azotobacter vinelandiiMutation(s): 0 
UniProt
Find proteins for P00214 (Azotobacter vinelandii)
Explore P00214 
Go to UniProtKB:  P00214
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00214
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SF4
Query on SF4

Download Ideal Coordinates CCD File 
B [auth A]IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-UHFFFAOYSA-N
F3S
Query on F3S

Download Ideal Coordinates CCD File 
C [auth A]FE3-S4 CLUSTER
Fe3 S4
FCXHZBQOKRZXKS-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Work: 0.206 
  • R-Value Observed: 0.206 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.2α = 90
b = 55.2β = 90
c = 95.1γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Released Date: 1993-10-31 
  • Deposition Author(s): Stout, C.D.

Revision History  (Full details and data files)

  • Version 1.0: 1993-10-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references, Derived calculations, Other