Solution NMR Structure of The Haemophilus Influenzae Iron-Sulfur Cluster Assembly Protein U (IscU) with Zinc Bound at the Active Site. Northeast Structural Genomics Consortium Target IR24. This protein is not apo, it is a model without zinc binding constraints.

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 25 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report

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Solution NMR structure of the iron-sulfur cluster assembly protein U (IscU) with zinc bound at the active site.

Ramelot, T.A.Cort, J.R.Goldsmith-Fischman, S.Kornhaber, G.J.Xiao, R.Shastry, R.Acton, T.B.Honig, B.Montelione, G.T.Kennedy, M.A.

(2004) J Mol Biol 344: 567-583

  • DOI: https://doi.org/10.1016/j.jmb.2004.08.038
  • Primary Citation of Related Structures:  
    1Q48, 1R9P

  • PubMed Abstract: 

    IscU is a highly conserved protein that serves as the scaffold for IscS-mediated assembly of iron-sulfur ([Fe-S]) clusters. We report the NMR solution structure of monomeric Haemophilus influenzae IscU with zinc bound at the [Fe-S] cluster assembly site. The compact core of the globular structure has an alpha-beta sandwich architecture with a three-stranded antiparallel beta-sheet and four alpha-helices. A nascent helix is located N-terminal to the core structure. The zinc is ligated by three cysteine residues and one histidine residue that are located in and near conformationally dynamic loops at one end of the IscU structure. Removal of the zinc metal by chelation results in widespread loss of structure in the apo form. The zinc-bound IscU may be a good model for iron-loaded IscU and may demonstrate structural features found in the [Fe-S] cluster bound form. Structural and functional similarities, genomic context in operons containing other homologous genes, and distributions of conserved surface residues support the hypothesis that IscU protein domains are homologous (i.e. derived from a common ancestor) with the SufE/YgdK family of [Fe-S] cluster assembly proteins.

  • Organizational Affiliation

    Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
NifU-like protein134Haemophilus influenzaeMutation(s): 0 
Gene Names: HI0377
Find proteins for Q57074 (Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd))
Explore Q57074 
Go to UniProtKB:  Q57074
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ57074
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 25 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report

Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2003-11-18
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2014-09-24
    Changes: Database references
  • Version 1.4: 2024-05-01
    Changes: Data collection, Database references