1HXU

OMPF PORIN MUTANT KK


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Role of charged residues at the OmpF porin channel constriction probed by mutagenesis and simulation.

Phale, P.S.Philippsen, A.Widmer, C.Phale, V.P.Rosenbusch, J.P.Schirmer, T.

(2001) Biochemistry 40: 6319-6325

  • Primary Citation of Related Structures:  1HXT, 1HXX

  • PubMed Abstract: 
  • The channel constriction of OmpF porin, a pore protein in the bacterial outer membrane, is highly charged due to the presence of three arginines (R42, R82, and R132) and two acidic residues (D113 and E117). The influence of these charges on ion condu ...

    The channel constriction of OmpF porin, a pore protein in the bacterial outer membrane, is highly charged due to the presence of three arginines (R42, R82, and R132) and two acidic residues (D113 and E117). The influence of these charges on ion conductance, ion selectivity, and voltage gating has been studied with mutants D113N/E117Q, R42A/R82A/R132A/D113N/E117Q, and V18K/G131K, which were designed to remove or add protein charge at the channel constriction. The crystal structures revealed no or only local changes compared to wild-type OmpF, thus allowing a comparative study. The single-channel conductance of the isosteric D113N/E117Q variant was found to be 2-fold reduced, and that of the pentuple mutant was 70% of the wild-type value, despite a considerably larger pore cross section. Ion selectivity was drastically altered by the mutations with cation/anion permeability ratios ranging from 1 to 12. Ion flow through these and eight other mutants, which have been characterized previously, was simulated by Brownian dynamics based on the detailed crystal structures. The calculated ion selectivity and relative channel conductance values agree well with the experimental data. This demonstrates that ion translocation through porin is mainly governed by pore geometry and charge, the two factors that are properly represented in the simulations.


    Organizational Affiliation

    Division of Microbiology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
OUTER MEMBRANE PROTEIN F
A
340Escherichia coli (strain K12)Gene Names: ompF (cmlB, coa, cry, tolF)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Beta-Barrel Membrane Proteins: Porins and Relatives
Protein: 
OmpF Porin
Find proteins for P02931 (Escherichia coli (strain K12))
Go to UniProtKB:  P02931
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.202 
  • Space Group: P 3 2 1
Unit Cell:
Length (Å)Angle (°)
a = 119.670α = 90.00
b = 119.670β = 90.00
c = 53.490γ = 120.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
REFMACrefinement
ROTAVATAdata scaling
CCP4data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-06-06
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2017-10-04
    Type: Advisory, Refinement description