3JZ3 | pdb_00003jz3

Structure of the cytoplasmic segment of histidine kinase QseC

• PDB DOI: https://doi.org/10.2210/pdb3JZ3/pdb

• Classification: TRANSFERASE
• Organism(s): Escherichia coli K-12
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2009-09-22 Released: 2010-07-21 
• Deposition Author(s): Xie, W., Kwiatkowski, W., Choe, S., Center for Structures of Membrane Proteins (CSMP)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 
  0.262 (Depositor), 0.290 (DCC) 
• R-Value Work: 
  0.228 (Depositor) 
• R-Value Observed: 
  0.230 (Depositor) 

Literature

Structure of the Cytoplasmic Segment of Histidine Kinase Receptor QseC, a Key Player in Bacterial Virulence.

Xie, W., Dickson, C., Kwiatkowski, W., Choe, S.

(2010) Protein Pept Lett 17: 1383-1391

• PubMed: 20594156 
• DOI: https://doi.org/10.2174/0929866511009011383
• Primary Citation Related Structures: 
  3JZ3


• PubMed Abstract: 
  

  QseC is a histidine kinase (HK) receptor involved in quorum sensing, a mechanism by which bacteria respond to fluctuations in cell population. We conducted a structural study of the cytoplasmic domain of QseC (QseC-CD) using X-ray crystallography. The 2.5 Å structure of the apo-enzyme revealed that the kinase domain of QseC retains the overall fold of the typical HK kinase domain. The construct that we used is inactive in the autokinase reaction and its inactivity is most likely caused by its atypical dimerization interface, as compared to that observed in the T.maritima HK cytoplasmic domain structure. Restoration of the activity may require that the entire dimerization domain be present in the protein construct. QseC, which plays an important role in bacterial pathogenesis, is a promising drug target and the structure of QseC-CD provides a platform for developing more potent inhibitors of pathogen virulence.

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Organizational Affiliation: 
• Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content 

• Total Structure Weight: 49.56 kDa 
• Atom Count: 2,357 
• Modeled Residue Count: 310 
• Deposited Residue Count: 444 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Sensor protein qseC	A, B	222	Escherichia coli K-12	Mutation(s): 0  Gene Names: qseC, ygiY, b3026, JW2994 EC: 2.7.13.3
UniProt
Find proteins for P40719 (Escherichia coli (strain K12)) Explore P40719  Go to UniProtKB:  P40719

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	C [auth B]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A, B	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free:  0.262 (Depositor), 0.290 (DCC) 
• R-Value Work:  0.228 (Depositor) 
• R-Value Observed: 0.230 (Depositor) 

Space Group: P 4₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 70.737	α = 90
b = 70.737	β = 90
c = 176.573	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
SOLVE	phasing
REFMAC	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2010-07-21 
Deposition Author(s): Xie, W., Kwiatkowski, W., Choe, S., Center for Structures of Membrane Proteins (CSMP)

Revision History  

• Version 1.0: 2010-07-21
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance
• Version 1.2: 2012-04-04
  Changes: Database references
• Version 1.3: 2024-11-27
  Changes: Data collection, Database references, Derived calculations, Structure summary