Solution Structure of HndAc : A Thioredoxin-like [2Fe-2S] Ferredoxin Involved in the NADP-reducing Hydrogenase Complex

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the least restraint violations 

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Solution structure of HndAc: a thioredoxin-like domain involved in the NADP-reducing hydrogenase complex

Nouailler, M.Morelli, X.Bornet, O.Chetrit, B.Dermoun, Z.Guerlesquin, F.

(2006) Protein Sci 15: 1369-1378

  • DOI: https://doi.org/10.1110/ps.051916606
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The NADP-reducing hydrogenase complex from Desulfovibrio fructosovorans is a heterotetramer encoded by the hndABCD operon. Sequence analysis indicates that the HndC subunit (52 kDa) corresponds to the NADP-reducing unit, and the HndD subunit (63.5 kDa) is homologous to Clostridium pasteurianum hydrogenase. The role of HndA and HndB subunits (18.8 kDa and 13.8 kDa, respectively) in the complex remains unknown. The HndA subunit belongs to the [2Fe-2S] ferredoxin family typified by C. pasteurianum ferredoxin. HndA is organized into two independent structural domains, and we report in the present work the NMR structure of its C-terminal domain, HndAc. HndAc has a thioredoxin-like fold consisting in four beta-strands and two relatively long helices. The [2Fe-2S] cluster is located near the surface of the protein and bound to four cysteine residues particularly well conserved in this class of proteins. Electron exchange between the HndD N-terminal [2Fe-2S] domain (HndDN) and HndAc has been previously evidenced, and in the present studies we have mapped the binding site of the HndDN domain on HndAc. A structural analysis of HndB indicates that it is a FeS subunit with 41% similarity with HndAc and it contains a possible thioredoxin-like fold. Our data let us propose that HndAc and HndB can form a heterodimeric intermediate in the electron transfer between the hydrogenase (HndD) active site and the NADP reduction site in HndC.

  • Organizational Affiliation

    Unité de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, Marseille Cedex 20, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
potential NAD-reducing hydrogenase subunit85Solidesulfovibrio fructosivoransMutation(s): 0 
Find proteins for Q46505 (Solidesulfovibrio fructosivorans)
Explore Q46505 
Go to UniProtKB:  Q46505
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ46505
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on FES

Download Ideal Coordinates CCD File 
Fe2 S2
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-06-27
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-03-09
    Changes: Data collection, Database references, Derived calculations