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 

wwPDB Validation 3D Report Full Report


This is version 1.1 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: 10.1021/acschembio.6b00431
  • Primary Citation of Related Structures:  

  • 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 c ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Methyl-accepting chemotaxis protein
A, B
188Caldanaerobacter subterraneus subsp. tengcongensis (strain DSM 15242 / JCM 11007 / NBRC 100824 / MB4)Mutation(s): 0 
Gene Names: Tar4
Find proteins for Q8RBX6 (Caldanaerobacter subterraneus subsp. tengcongensis (strain DSM 15242 / JCM 11007 / NBRC 100824 / MB4))
Go to UniProtKB:  Q8RBX6
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
A, B
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
CMO
Query on CMO

Download SDF File 
Download CCD File 
A, B
CARBON MONOXIDE
C O
UGFAIRIUMAVXCW-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 90.865α = 90.00
b = 127.205β = 95.79
c = 42.699γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
PHENIXrefinement
MOLREPphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-07-06
    Type: Initial release
  • Version 1.1: 2016-08-31
    Type: Database references