1PMM

Crystal structure of Escherichia coli GadB (low pH)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.182 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Crystal structure and functional analysis of escherichia coli glutamate decarboxylase

Capitani, G.De Biase, D.Aurizi, C.Gut, H.Bossa, F.Grutter, M.G.

(2003) EMBO J 22: 4027-4037

  • DOI: 10.1093/emboj/cdg403
  • Primary Citation of Related Structures:  
    1PMM, 1PMO

  • PubMed Abstract: 
  • Glutamate decarboxylase is a vitamin B6-dependent enzyme, which catalyses the decarboxylation of glutamate to gamma-aminobutyrate. In Escherichia coli, expression of glutamate decarboxylase (GadB), a 330 kDa hexamer, is induced to maintain the physiological pH under acidic conditions, like those of the passage through the stomach en route to the intestine ...

    Glutamate decarboxylase is a vitamin B6-dependent enzyme, which catalyses the decarboxylation of glutamate to gamma-aminobutyrate. In Escherichia coli, expression of glutamate decarboxylase (GadB), a 330 kDa hexamer, is induced to maintain the physiological pH under acidic conditions, like those of the passage through the stomach en route to the intestine. GadB, together with the antiporter GadC, constitutes the gad acid resistance system, which confers the ability for bacterial survival for at least 2 h in a strongly acidic environment. GadB undergoes a pH-dependent conformational change and exhibits an activity optimum at low pH. We determined the crystal structures of GadB at acidic and neutral pH. They reveal the molecular details of the conformational change and the structural basis for the acidic pH optimum. We demonstrate that the enzyme is localized exclusively in the cytoplasm at neutral pH, but is recruited to the membrane when the pH falls. We show by structure-based site-directed mutagenesis that the triple helix bundle formed by the N-termini of the protein at acidic pH is the major determinant for this behaviour.


    Organizational Affiliation

    Biochemisches Institut der Universität Zürich, Zürich CH-8057, Switzerland. capitani@bioc.unizh.ch



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Glutamate decarboxylase beta
A, B, C, D, E, F
A, B, C, D, E, F
466Escherichia coliMutation(s): 0 
Gene Names: gadB
EC: 4.1.1.15
UniProt
Find proteins for P69910 (Escherichia coli (strain K12))
Explore P69910 
Go to UniProtKB:  P69910
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP69910
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.182 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 90.78α = 76.8
b = 91.406β = 77.1
c = 93.686γ = 78.24
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
CNSrefinement

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-02-17
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance