1CEI

STRUCTURE DETERMINATION OF THE COLICIN E7 IMMUNITY PROTEIN (IMME7) THAT BINDS SPECIFICALLY TO THE DNASE-TYPE COLICIN E7 AND INHIBITS ITS BACTERIOCIDAL ACTIVITY


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The crystal structure of the immunity protein of colicin E7 suggests a possible colicin-interacting surface.

Chak, K.F.Safo, M.K.Ku, W.Y.Hsieh, S.Y.Yuan, H.S.

(1996) Proc Natl Acad Sci U S A 93: 6437-6442

  • DOI: https://doi.org/10.1073/pnas.93.13.6437
  • Primary Citation of Related Structures:  
    1CEI

  • PubMed Abstract: 

    The immunity protein of colicin E7 (ImmE7) can bind specifically to the DNase-type colicin E7 and inhibit its bactericidal activity. Here we report the 1.8-angstrom crystal structure of the ImmE7 protein. This is the first x-ray structure determined in the superfamily of colicin immunity proteins. The ImmE7 protein consists of four antiparallel alpha-helices, folded in a topology similar to the architecture of a four-helix bundle structure. A region rich in acidic residues is identified. This negatively charged area has the greatest variability within the family of DNase-type immunity proteins; thus, it seems likely that this area is involved in specific binding to colicin. Based on structural, genetic, and kinetic data, we suggest that all the DNase-type immunity proteins, as well as colicins, share a "homologous-structural framework" and that specific interaction between a colicin and its cognate immunity protein relies upon how well these two proteins' charged residues match on the interaction surface, thus leading to specific immunity of the colicin.


  • Organizational Affiliation

    Institute of Biochemistry, National Yang-Ming University, Taipei, Taiwan, Republic of China.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
COLICIN E7 IMMUNITY PROTEIN94Escherichia coliMutation(s): 0 
UniProt
Find proteins for Q03708 (Escherichia coli)
Explore Q03708 
Go to UniProtKB:  Q03708
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ03708
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 75.14α = 90
b = 50.48β = 90
c = 45.36γ = 90
Software Package:
Software NamePurpose
X-PLORrefinement
MSCdata reduction
MSCdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-03-12
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references, Other