5U56

Structure of Francisella tularensis heterodimeric SspA (MglA-SspA)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Dissection of the molecular circuitry controlling virulence in Francisella tularensis.

Cuthbert, B.J.Ross, W.Rohlfing, A.E.Dove, S.L.Gourse, R.L.Brennan, R.G.Schumacher, M.A.

(2017) Genes Dev. 31: 1549-1560

  • DOI: 10.1101/gad.303701.117
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Francisella tularensis, the etiological agent of tularemia, is one of the most infectious bacteria known. Because of its extreme pathogenicity, F. tularensis is classified as a category A bioweapon by the US government. F. tularensis virulence stems ...

    Francisella tularensis, the etiological agent of tularemia, is one of the most infectious bacteria known. Because of its extreme pathogenicity, F. tularensis is classified as a category A bioweapon by the US government. F. tularensis virulence stems from genes encoded on the Francisella pathogenicity island (FPI). An unusual set of Francisella regulators-the heteromeric macrophage growth locus protein A (MglA)-stringent starvation protein A (SspA) complex and the DNA-binding protein pathogenicity island gene regulator (PigR)-activates FPI transcription and thus is essential for virulence. Intriguingly, the second messenger, guanosine-tetraphosphate (ppGpp), which is produced during infection, is also involved in coordinating Francisella virulence; however, its role has been unclear. Here we identify MglA-SspA as a novel ppGpp-binding complex and describe structures of apo- and ppGpp-bound MglA-SspA. We demonstrate that MglA-SspA, which binds RNA polymerase (RNAP), also interacts with the C-terminal domain of PigR, thus anchoring the (MglA-SspA)-RNAP complex to the FPI promoter. Furthermore, we show that MglA-SspA must be bound to ppGpp to mediate high-affinity interactions with PigR. Thus, these studies unveil a novel pathway different from those described previously for regulation of transcription by ppGpp. The data also indicate that F. tularensis pathogenesis is controlled by a highly interconnected molecular circuitry in which the virulence machinery directly senses infection via a small molecule stress signal.


    Organizational Affiliation

    Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Stringent starvation protein A
C, D
211Francisella tularensis subsp. tularensis (strain SCHU S4 / Schu 4)Mutation(s): 0 
Gene Names: sspA
Find proteins for Q5NHJ6 (Francisella tularensis subsp. tularensis (strain SCHU S4 / Schu 4))
Go to UniProtKB:  Q5NHJ6
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Macrophage growth locus A
A, B
204Francisella tularensis subsp. tularensis (strain SCHU S4 / Schu 4)Mutation(s): 0 
Gene Names: mglA
Find proteins for Q5NFG1 (Francisella tularensis subsp. tularensis (strain SCHU S4 / Schu 4))
Go to UniProtKB:  Q5NFG1
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A, B, C, D
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
PRO
Query on PRO

Download SDF File 
Download CCD File 
A, B
PROLINE
C5 H9 N O2
ONIBWKKTOPOVIA-BYPYZUCNSA-N
 Ligand Interaction
1PE
Query on 1PE

Download SDF File 
Download CCD File 
A, C
PENTAETHYLENE GLYCOL
PEG400
C10 H22 O6
JLFNLZLINWHATN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.204 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 66.408α = 90.00
b = 113.261β = 90.00
c = 140.400γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
PHASERphasing
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-08-16
    Type: Initial release
  • Version 1.1: 2017-09-27
    Type: Database references