Crystal Structure of Escherichia coli SufA Involved in Biosynthesis of Iron-sulfur Clusters

Experimental Data Snapshot

  • Resolution: 2.70 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.232 

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Crystal structure of Escherichia coli SufA involved in biosynthesis of iron-sulfur clusters: Implications for a functional dimer

Wada, K.Hasegawa, Y.Gong, Z.Minami, Y.Fukuyama, K.Takahashi, Y.

(2005) FEBS Lett 579: 6543-6548

  • DOI: https://doi.org/10.1016/j.febslet.2005.10.046
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    IscA and SufA are paralogous proteins that play crucial roles in the biosynthesis of Fe-S clusters, perhaps through a mechanism involving transient Fe-S cluster formation. We have determined the crystal structure of E. coli SufA at 2.7A resolution. SufA exists as a homodimer, in contrast to the tetrameric organization of IscA. Furthermore, a C-terminal segment containing two essential cysteine residues (Cys-Gly-Cys), which is disordered in the IscA structure, is clearly visible in one molecule (the alpha1 subunit) of the SufA homodimer. Although this segment is disordered in the other molecule (the alpha2 subunit), computer modeling of this segment based on the well-defined conformation of alpha1 subunit suggests that the four cysteine residues (Cys114 and Cys116 in each subunit) in the Cys-Gly-Cys motif are positioned in close proximity at the dimer interface. The arrangement of these cysteines together with the nearby Glu118 in SufA dimer may allow coordination of an Fe-S cluster and/or an Fe atom.

  • Organizational Affiliation

    Department of Biology, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
SufA protein
A, B
145Escherichia coliMutation(s): 0 
Find proteins for P77667 (Escherichia coli (strain K12))
Explore P77667 
Go to UniProtKB:  P77667
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP77667
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.70 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.232 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 25.162α = 90
b = 88.5β = 90
c = 122.013γ = 90
Software Package:
Software NamePurpose
MAR345data collection
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-12-13
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2023-10-25
    Changes: Data collection, Database references, Refinement description