Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

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

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

Biological Assembly 2  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

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

Biological assembly 2 assigned by authors and generated by PISA (software)

Biological Assembly 3  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

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

Biological assembly 3 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 546967.63 
• Atom Count: 35538 
• Residue Count: 4770 
• Unique protein chains: 1

4A2L

Structure of the periplasmic domain of the heparin and heparan sulphate sensing hybrid two component system BT4663 in apo and ligand bound forms

• DOI: 10.2210/pdb4A2L/pdb

• Classification: TRANSCRIPTION
• Organism(s): Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / NCTC 10582 / E50 / VPI-5482)
• Expression System: Escherichia coli BL21


• Deposited: 2011-09-27 Released: 2012-05-02 
• Deposition Author(s): Lowe, E.C., Basle, A., Czjzek, M., Firbank, S.J., Bolam, D.N.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.231 
• R-Value Work: 0.186 

Literature

A Scissor Blade-Like Closing Mechanism Implicated in Transmembrane Signaling in a Bacteroides Hybrid Two-Component System.

Lowe, E.C., Basle, A., Czjzek, M., Firbank, S.J., Bolam, D.N.

(2012) Proc.Natl.Acad.Sci.USA 109: 7298

• PubMed: 22532667 
• DOI: 10.1073/pnas.1200479109
• Primary Citation of Related Structures:  
  4A2M


• PubMed Abstract: 
  

Signaling across the membrane in response to extracellular stimuli is essential for survival of all cells. In bacteria, responses to environmental changes are predominantly mediated by two-component systems, which are typically composed of a membrane-spanning sensor histidine kinase and a cytoplasmic response regulator. In the human gut symbiont Bacteroides thetaiotaomicron, hybrid two-component systems are a key part of the bacterium's ability to sense and degrade complex carbohydrates in the gut. Here, we identify the activating ligand of the hybrid two-component system, BT4663, which controls heparin and heparan sulfate acquisition and degradation in this prominent gut microbe, and report the crystal structure of the extracellular sensor domain in both apo and ligand-bound forms. Current models for signal transduction across the membrane involve either a piston-like or rotational displacement of the transmembrane helices to modulate activity of the linked cytoplasmic kinases. The structures of the BT4663 sensor domain reveal a significant conformational change in the homodimer on ligand binding, which results in a scissor-like closing of the C-termini of each protomer. We propose this movement activates the attached intracellular kinase domains and represents an allosteric mechanism for bacterial transmembrane signaling distinct from previously described models, thus expanding our understanding of signal transduction across the membrane, a fundamental requirement in many important biological processes.

---

Organizational Affiliation: 

Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
TWO-COMPONENT SYSTEM SENSOR HISTIDINE KINASE/RESPONSE	A, B, C, D, E, F	795	Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / NCTC 10582 / E50 / VPI-5482)	Mutation(s): 0
Find proteins for Q89YR8 (Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / NCTC 10582 / E50 / VPI-5482)) Go to UniProtKB:  Q89YR8

Small Molecules

Ligands 7 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
2PE	D	NONAETHYLENE GLYCOL C18 H38 O10 YZUUTMGDONTGTN-UHFFFAOYSA-N
EDO	A, B, C, D	1,2-ETHANEDIOL ETHYLENE GLYCOL C2 H6 O2 LYCAIKOWRPUZTN-UHFFFAOYSA-N
PG4	B	TETRAETHYLENE GLYCOL C8 H18 O5 UWHCKJMYHZGTIT-UHFFFAOYSA-N
OAA	C, E	OXALOACETATE ION C4 H3 O5 KHPXUQMNIQBQEV-UHFFFAOYSA-M
PGE	A, B, E, F	TRIETHYLENE GLYCOL C6 H14 O4 ZIBGPFATKBEMQZ-UHFFFAOYSA-N
PEG	A, B, C, D, E, F	DI(HYDROXYETHYL)ETHER C4 H10 O3 MTHSVFCYNBDYFN-UHFFFAOYSA-N
MES	B, D, E	2-(N-MORPHOLINO)-ETHANESULFONIC ACID C6 H13 N O4 S SXGZJKUKBWWHRA-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.231 
• R-Value Work: 0.186 
• Space Group: P 3 2 1

Unit Cell:

Length (Å)	Angle (°)
a = 342.468	α = 90.00
b = 342.468	β = 90.00
c = 97.852	γ = 120.00

Software Package:

Software Name	Purpose
SCALA	data scaling
SHELXCDE	phasing
REFMAC	refinement
iMOSFLM	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-09-27 
• Released Date: 2012-05-02 
• Deposition Author(s): Lowe, E.C., Basle, A., Czjzek, M., Firbank, S.J., Bolam, D.N.

Revision History 

• Version 1.0: 2012-05-02
  Type: Initial release
• Version 1.1: 2012-05-23
  Type: Other
• Version 1.2: 2014-11-19
  Type: Data collection