2E2E

TPR domain of NrfG mediates the complex formation between heme lyase and formate-dependent nitrite reductase in Escherichia Coli O157:H7


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.231 
  • R-Value Observed: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

TPR domain of NrfG mediates complex formation between heme lyase and formate-dependent nitrite reductase in Escherichia coli O157:H7.

Han, D.Kim, K.Oh, J.Park, J.Kim, Y.

(2008) Proteins 70: 900-914

  • DOI: 10.1002/prot.21597
  • Primary Citation of Related Structures:  
    2E2E

  • PubMed Abstract: 
  • Escherichia coli synthesize C-type cytochromes only during anaerobic growth in media supplemented with nitrate and nitrite. The reduction of nitrate to ammonium in the periplasm of Escherichia coli involves two separate periplasmic enzymes, nitrate r ...

    Escherichia coli synthesize C-type cytochromes only during anaerobic growth in media supplemented with nitrate and nitrite. The reduction of nitrate to ammonium in the periplasm of Escherichia coli involves two separate periplasmic enzymes, nitrate reductase and nitrite reductase. The nitrite reductase involved, NrfA, contains cytochrome C and is synthesized coordinately with a membrane-associated cytochrome C, NrfB, during growth in the presence of nitrite or in limiting nitrate concentrations. The genes NrfE, NrfF, and NrfG are required for the formate-dependent nitrite reduction pathway, which involves at least two C-type cytochrome proteins, NrfA and NrfB. The NrfE, NrfF, and NrfG genes (heme lyase complex) are involved in the maturation of a special C-type cytochrome, apocytochrome C (apoNrfA), to cytochrome C (NrfA) by transferring a heme to the unusual heme binding motif of the Cys-Trp-Ser-Cys-Lys sequence in apoNrfA protein. Thus, in order to further investigate the roles of NrfG in the formation of heme lyase complex (NrfEFG) and in the interaction between heme lyase complex and formate-dependent nitrite reductase (NrfA), we determined the crystal structure of NrfG at 2.05 A. The structure of NrfG showed that the contact between heme lyase complex (NrfEFG) and NrfA is accomplished via a TPR domain in NrfG which serves as a binding site for the C-terminal motif of NrfA. The portion of NrfA that binds to TPR domain of NrfG has a unique secondary motif, a helix followed by about a six-residue C-terminal loop (the so called "hook conformation"). This study allows us to better understand the mechanism of special C-type cytochrome assembly during the maturation of formate-dependent nitrite reductase, and also adds a new TPR binding conformation to the list of TPR-mediated protein-protein interactions.


    Organizational Affiliation

    College of Medicine, Seoul National University, Yongon-Dong, Seoul 110-799, Korea.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Formate-dependent nitrite reductase complex nrfG subunitAB177Escherichia coliMutation(s): 0 
Gene Names: nrfG
Find proteins for Q8X5S3 (Escherichia coli O157:H7)
Explore Q8X5S3 
Go to UniProtKB:  Q8X5S3
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BME
Query on BME

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A, B
BETA-MERCAPTOETHANOL
C2 H6 O S
DGVVWUTYPXICAM-UHFFFAOYSA-N
 Ligand Interaction
IMD
Query on IMD

Download CCD File 
A, B
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.231 
  • R-Value Observed: 0.235 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.802α = 90
b = 85.824β = 89.99
c = 49.073γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling
SOLVEphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-10-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance