Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

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

Macromolecule Content

• Total Structure Weight: 35.30 kDa 
• Atom Count: 2549 
• Modelled Residue Count: 278 
• Deposited Residue Count: 280 
• Unique protein chains: 1

2X9K

Structure of a E.coli porin

• DOI: 10.2210/pdb2X9K/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Escherichia coli K-12
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2010-03-21 Released: 2011-01-26 
• Deposition Author(s): Korkmaz-Ozkan, F., Koster, S., Kuhlbrandt, W., Mantele, W., Yildiz, O.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.18 Å
• R-Value Free: 0.248 
• R-Value Work: 0.213 
• R-Value Observed: 0.215 

Literature

Correlation between the Ompg Secondary Structure and its Ph-Dependent Alterations Monitored by Ftir.

Korkmaz-Ozkan, F., Koster, S., Kuhlbrandt, W., Mantele, W., Yildiz, O.

(2010) J Mol Biol 401: 56

• PubMed: 20561532 
• DOI: 10.1016/j.jmb.2010.06.015
• Primary Citation of Related Structures:  
  2X9K


• PubMed Abstract: 
  

The channel activity of the outer-membrane protein G (OmpG) from Escherichia coli is pH-dependent. To investigate the role of the histidine pair His231/His261 in triggering channel opening and closing, we mutated both histidines to alanines and cysteines. Fourier transform infrared spectra revealed that the OmpG mutants stay-independent of pH-in an open conformation. Temperature ramp experiments indicate that the mutants are as stable as the open state of wild-type OmpG. The X-ray structure of the alanine-substituted OmpG mutant obtained at pH 6.5 confirms the constitutively open conformation. Compared to previous structures of the wild-type protein in the open and closed conformation, the mutant structure shows a difference in the extracellular loop L6 connecting beta-strands S12 and S13. A deletion of amino acids 220-228, which are thought to block the channel at low pH in wild-type OmpG, indicates conformational changes, which might be triggered by His231/His261.

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Organizational Affiliation: 

Institute of Biophysics, Goethe-University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
OUTER MEMBRANE PROTEIN G	A	280	Escherichia coli K-12	Mutation(s): 2  Gene Names: ompG, b1319, JW1312
Membrane protein Mpstruc	Group:  TRANSMEMBRANE PROTEINS: BETA-BARREL		Sub Group:  Beta-Barrel Membrane Proteins: Porins and Relatives	Protein:  OmpG *monomeric* porin
Find proteins for P76045 (Escherichia coli (strain K12)) Explore P76045  Go to UniProtKB:  P76045

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
BOG	B [auth A],  C [auth A],  D [auth A],  E [auth A],  F [auth A],  G [auth A],  H [auth A],  I [auth A],  J [auth A]	octyl beta-D-glucopyranoside C14 H28 O6 HEGSGKPQLMEBJL-RKQHYHRCSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.18 Å
• R-Value Free: 0.248 
• R-Value Work: 0.213 
• R-Value Observed: 0.215 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 55.61	α = 90
b = 70.96	β = 90
c = 119.17	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
XSCALE	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2010-03-21 
• Released Date: 2011-01-26 
Deposition Author(s): Korkmaz-Ozkan, F., Koster, S., Kuhlbrandt, W., Mantele, W., Yildiz, O.

Revision History  

• Version 1.0: 2011-01-26
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2018-01-24
  Changes: Source and taxonomy
• Version 1.4: 2020-07-29
  Type: Remediation
  Reason: Carbohydrate remediation
  Changes: Advisory, Data collection, Derived calculations, Other, Structure summary