5COS

Crystal Structure of the Cytoplasmic Domain of the Pseudomonas putida Anti-sigma Factor PupR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.215 
  • R-Value Observed: 0.218 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Mechanistic Implications of the Unique Structural Features and Dimerization of the Cytoplasmic Domain of the Pseudomonas Sigma Regulator, PupR.

Jensen, J.L.Balbo, A.Neau, D.B.Chakravarthy, S.Zhao, H.Sinha, S.C.Colbert, C.L.

(2015) Biochemistry 54: 5867-5877

  • DOI: 10.1021/acs.biochem.5b00826
  • Primary Citation of Related Structures:  
    5COS, 5CAM

  • PubMed Abstract: 
  • Gram-negative bacteria tightly regulate intracellular levels of iron, an essential nutrient. To ensure this strict control, some outer membrane TonB-dependent transporters (TBDTs) that are responsible for iron import stimulate their own transcription in response to extracellular binding by an iron-laden siderophore ...

    Gram-negative bacteria tightly regulate intracellular levels of iron, an essential nutrient. To ensure this strict control, some outer membrane TonB-dependent transporters (TBDTs) that are responsible for iron import stimulate their own transcription in response to extracellular binding by an iron-laden siderophore. This process is mediated by an inner membrane sigma regulator protein (an anti-sigma factor) that transduces an unknown periplasmic signal from the TBDT to release an intracellular sigma factor from the inner membrane, which ultimately upregulates TBDT transcription. Here, we use the Pseudomonas putida ferric-pseudobactin BN7/BN8 sigma regulator, PupR, as a model system to understand the molecular mechanism of this conserved class of sigma regulators. We have determined the X-ray crystal structure of the cytoplasmic anti-sigma domain (ASD) of PupR to 2.0 Å. Size exclusion chromatography, small-angle X-ray scattering, and sedimentation velocity analytical ultracentrifugation all indicate that, in contrast to other ASDs, the PupR-ASD exists as a dimer in solution. Mutagenesis of residues at the dimer interface identified from the crystal structure disrupts dimerization and protein stability, as determined by sedimentation velocity analytical ultracentrifugation and thermal denaturation circular dichroism spectroscopy. These combined results suggest that this type of inner membrane sigma regulator may utilize an unusual mechanism to sequester their cognate sigma factors and prevent transcription activation.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58108-6050, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Siderophore-interacting proteinA, B, C, D86Pseudomonas capeferrumMutation(s): 0 
Gene Names: PC358_08100
UniProt
Find proteins for A0A084CH09 (Pseudomonas capeferrum)
Explore A0A084CH09 
Go to UniProtKB:  A0A084CH09
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.215 
  • R-Value Observed: 0.218 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 33.459α = 90
b = 134.621β = 113.72
c = 34.896γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States1R15GM113227-01

Revision History  (Full details and data files)

  • Version 1.0: 2015-09-09
    Type: Initial release
  • Version 1.1: 2015-10-28
    Changes: Database references
  • Version 1.2: 2017-09-20
    Changes: Advisory, Author supporting evidence, Database references, Derived calculations
  • Version 1.3: 2019-12-25
    Changes: Author supporting evidence