5JRX

Crystal structure of Fe(II) CO-bound H-NOX protein from C. subterraneus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.188 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Structural and Functional Evidence Indicates Selective Oxygen Signaling in Caldanaerobacter subterraneus H-NOX.

Hespen, C.W.Bruegger, J.J.Phillips-Piro, C.M.Marletta, M.A.

(2016) ACS Chem Biol 11: 2337-2346

  • DOI: https://doi.org/10.1021/acschembio.6b00431
  • Primary Citation of Related Structures:  
    5JRU, 5JRV, 5JRX

  • PubMed Abstract: 

    Acute and specific sensing of diatomic gas molecules is an essential facet of biological signaling. Heme nitric oxide/oxygen binding (H-NOX) proteins are a family of gas sensors found in diverse classes of bacteria and eukaryotes. The most commonly characterized bacterial H-NOX domains are from facultative anaerobes and are activated through a conformational change caused by formation of a 5-coordinate Fe(II)-NO complex. Members of this H-NOX subfamily do not bind O2 and therefore can selectively ligate NO even under aerobic conditions. In contrast, H-NOX domains encoded by obligate anaerobes do form stable 6-coordinate Fe(II)-O2 complexes by utilizing a conserved H-bonding network in the ligand-binding pocket. The biological function of O2-binding H-NOX domains has not been characterized. In this work, the crystal structures of an O2-binding H-NOX domain from the thermophilic obligate anaerobe Caldanaerobacter subterraneus (Cs H-NOX) in the Fe(II)-NO, Fe(II)-CO, and Fe(II)-unliganded states are reported. The Fe(II)-unliganded structure displays a conformational shift distinct from the NO-, CO-, and previously reported O2-coordinated structures. In orthogonal signaling assays using Cs H-NOX and the H-NOX signaling effector histidine kinase from Vibrio cholerae (Vc HnoK), Cs H-NOX regulates Vc HnoK in an O2-dependent manner and requires the H-bonding network to distinguish O2 from other ligands. The crystal structures of Fe(II) unliganded and NO- and CO-bound Cs H-NOX combined with functional assays herein provide the first evidence that H-NOX proteins from obligate anaerobes can serve as O2 sensors.


  • Organizational Affiliation

    Department of Molecular and Cell Biology, University of California-Berkeley , 356 Stanley Hall, Berkeley, California 94720-3220, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Methyl-accepting chemotaxis protein
A, B
188Caldanaerobacter subterraneus subsp. tengcongensis MB4Mutation(s): 0 
Gene Names: Tar4TTE0680
UniProt
Find proteins for Q8RBX6 (Caldanaerobacter subterraneus subsp. tengcongensis (strain DSM 15242 / JCM 11007 / NBRC 100824 / MB4))
Explore Q8RBX6 
Go to UniProtKB:  Q8RBX6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8RBX6
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.188 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 90.865α = 90
b = 127.205β = 95.79
c = 42.699γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-07-06
    Type: Initial release
  • Version 1.1: 2016-08-31
    Changes: Database references
  • Version 1.2: 2023-09-27
    Changes: Data collection, Database references, Derived calculations, Refinement description