2VV7

BJFIXLH IN UNLIGANDED FERROUS FORM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.81 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Changes in Quaternary Structure in the Signaling Mechanisms of Pas Domains.

Ayers, R.A.Moffat, K.

(2008) Biochemistry 47: 12078

  • DOI: 10.1021/bi801254c
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • FixL from Bradyrhizobium japonicum is a PAS sensor protein in which two PAS domains covalently linked to a histidine kinase domain are responsible for regulating nitrogen fixation in an oxygen-dependent manner. The more C-terminal PAS domain, denoted ...

    FixL from Bradyrhizobium japonicum is a PAS sensor protein in which two PAS domains covalently linked to a histidine kinase domain are responsible for regulating nitrogen fixation in an oxygen-dependent manner. The more C-terminal PAS domain, denoted bjFixLH, contains a heme cofactor that binds diatomic molecules such as carbon monoxide and oxygen and regulates the activity of the FixL histidine kinase as part of a two-component signaling system. We present the structures of ferric, deoxy, and carbon monoxide-bound bjFixLH in a new space group ( P1) and at resolutions (1.5-1.8 A) higher than the resolutions of those previously obtained. Interestingly, bjFixLH can form two different dimers (in P1 and R32 crystal forms) in the same crystallization solution, where the monomers in one dimer are rotated approximately 175 degrees relative to the second. This suggests that PAS monomers are plastic and that two quite distinct quaternary structures are closely similar in free energy. We use screw rotation analysis to carry out a quantitative pairwise comparison of PAS quaternary structures, which identifies five different relative orientations adopted by isolated PAS monomers. We conclude that PAS monomer arrangement is context-dependent and could differ depending on whether the PAS domains are isolated or are part of a full-length protein. Structurally homologous residues comprise a conserved dimer interface. Using network analysis, we find that the architecture of the PAS dimer interface is continuous rather than modular; the network of residues comprising the interface is strongly connected. A continuous dimer interface is consistent with the low dimer-monomer dissociation equilibrium constant. Finally, we quantitate quaternary structural changes induced by carbon monoxide binding to a bjFixLH dimer, in which monomers rotate by up to approximately 2 degrees relative to each other. We relate these changes to those in other dimeric PAS domains and discuss the role of quaternary structural changes in the signaling mechanisms of PAS sensor proteins.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SENSOR PROTEIN FIXL
A, B, C, D
119Bradyrhizobium japonicumMutation(s): 0 
EC: 2.7.13.3 (PDB Primary Data), 2.7.3 (PDB Primary Data)
Find proteins for P23222 (Bradyrhizobium diazoefficiens (strain JCM 10833 / IAM 13628 / NBRC 14792 / USDA 110))
Go to UniProtKB:  P23222
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A, B, C, D
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
CL
Query on CL

Download CCD File 
A, C
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
NA
Query on NA

Download CCD File 
C
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.81 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.646α = 73.19
b = 49.814β = 71.12
c = 58.76γ = 71.74
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
EPMRphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-11-04
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2019-01-30
    Changes: Data collection, Experimental preparation, Other
  • Version 1.3: 2019-02-06
    Changes: Data collection, Experimental preparation