2DGM

Crystal structure of Escherichia coli GadB in complex with iodide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.227 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Escherichia coli acid resistance: pH-sensing, activation by chloride and autoinhibition in GadB

Gut, H.Pennacchietti, E.John, R.A.Bossa, F.Capitani, G.De Biase, D.Gruetter, M.G.

(2006) Embo J. 25: 2643-2651

  • DOI: 10.1038/sj.emboj.7601107
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Escherichia coli and other enterobacteria exploit the H+ -consuming reaction catalysed by glutamate decarboxylase to survive the stomach acidity before reaching the intestine. Here we show that chloride, extremely abundant in gastric secretions, is a ...

    Escherichia coli and other enterobacteria exploit the H+ -consuming reaction catalysed by glutamate decarboxylase to survive the stomach acidity before reaching the intestine. Here we show that chloride, extremely abundant in gastric secretions, is an allosteric activator producing a 10-fold increase in the decarboxylase activity at pH 5.6. Cooperativity and sensitivity to chloride were lost when the N-terminal 14 residues, involved in the formation of two triple-helix bundles, were deleted by mutagenesis. X-ray structures, obtained in the presence of the substrate analogue acetate, identified halide-binding sites at the base of each N-terminal helix, showed how halide binding is responsible for bundle stability and demonstrated that the interconversion between active and inactive forms of the enzyme is a stepwise process. We also discovered an entirely novel structure of the cofactor pyridoxal 5'-phosphate (aldamine) to be responsible for the reversibly inactivated enzyme. Our results link the entry of chloride ions, via the H+/Cl- exchange activities of ClC-ec1, to the trigger of the acid stress response in the cell when the intracellular proton concentration has not yet reached fatal values.


    Related Citations: 
    • Crystal structure and functional analysis of Escherichia coli glutamate decarboxylase
      Capitani, G.,De Biase, D.,Aurizi, C.,Gut, H.,Bossa, F.,Gruetter, M.G.
      (2003) Embo J. 22: 4027


    Organizational Affiliation

    Biochemisches Institut der Universität Zürich, Zürich, Switzerland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutamate decarboxylase beta
A, B, C, D, E, F
466Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: gadB
EC: 4.1.1.15
Find proteins for P69910 (Escherichia coli (strain K12))
Go to UniProtKB:  P69910
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IOD
Query on IOD

Download SDF File 
Download CCD File 
A, B, C, D, E, F
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
 Ligand Interaction
FMT
Query on FMT

Download SDF File 
Download CCD File 
A, B, C, D, E, F
FORMIC ACID
C H2 O2
BDAGIHXWWSANSR-UHFFFAOYSA-N
 Ligand Interaction
PEG
Query on PEG

Download SDF File 
Download CCD File 
E
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
ACY
Query on ACY

Download SDF File 
Download CCD File 
E
ACETIC ACID
C2 H4 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-N
 Ligand Interaction
PLP
Query on PLP

Download SDF File 
Download CCD File 
A, B, C, D, E, F
PYRIDOXAL-5'-PHOSPHATE
VITAMIN B6 Phosphate
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.227 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 91.336α = 76.65
b = 91.804β = 76.94
c = 93.914γ = 78.04
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-06-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance