1A6L

T14C MUTANT OF AZOTOBACTER VINELANDII FDI


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A T14C variant of Azotobacter vinelandii ferredoxin I undergoes facile [3Fe-4S]0 to [4Fe-4S]2+ conversion in vitro but not in vivo.

Gao-Sheridan, H.S.Kemper, M.A.Khayat, R.Tilley, G.J.Armstrong, F.A.Sridhar, V.Prasad, G.S.Stout, C.D.Burgess, B.K.

(1998) J.Biol.Chem. 273: 33692-33701


  • PubMed Abstract: 
  • [4Fe-4S]2+/+ clusters that are ligated by Cys-X-X-Cys-X-X-Cys sequence motifs share the general feature of being hard to convert to [3Fe-4S]+/0 clusters, whereas those that contain a Cys-X-X-Asp-X-X-Cys motif undergo facile and reversible cluster int ...

    [4Fe-4S]2+/+ clusters that are ligated by Cys-X-X-Cys-X-X-Cys sequence motifs share the general feature of being hard to convert to [3Fe-4S]+/0 clusters, whereas those that contain a Cys-X-X-Asp-X-X-Cys motif undergo facile and reversible cluster interconversion. Little is known about the factors that control the in vivo assembly and conversion of these clusters. In this study we have designed and constructed a 3Fe to 4Fe cluster conversion variant of Azotobacter vinelandii ferredoxin I (FdI) in which the sequence that ligates the [3Fe-4S] cluster in native FdI was altered by converting a nearby residue, Thr-14, to Cys. Spectroscopic and electrochemical characterization shows that when purified in the presence of dithionite, T14C FdI is an O2-sensitive 8Fe protein. Both the new and the indigenous clusters have reduction potentials that are significantly shifted compared with those in native FdI, strongly suggesting a significantly altered environment around the clusters. Interestingly, whole cell EPR have revealed that T14C FdI exists as a 7Fe protein in vivo. This 7Fe form of T14C FdI is extremely similar to native FdI in its spectroscopic, electrochemical, and structural features. However, unlike native FdI which does not undergo facile cluster conversion, the 7Fe form T14C FdI quickly converts to the 8Fe form with a high efficiency under reducing conditions.


    Organizational Affiliation

    Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-3900, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
FERREDOXIN
A
106Azotobacter vinelandiiGene Names: fdxA
Find proteins for P00214 (Azotobacter vinelandii)
Go to UniProtKB:  P00214
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SF4
Query on SF4

Download SDF File 
Download CCD File 
A
IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-VKOJMFJBAC
 Ligand Interaction
F3S
Query on F3S

Download SDF File 
Download CCD File 
A
FE3-S4 CLUSTER
Fe3 S4
FCXHZBQOKRZXKS-MZMDZPPWAW
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Work: 0.206 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 55.880α = 90.00
b = 55.880β = 90.00
c = 96.400γ = 90.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORmodel building
X-PLORrefinement
XENGENdata scaling
XENGENdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-05-27
    Type: Initial release
  • Version 1.1: 2008-03-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance