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 

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This is version 1.2 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: 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 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
MoleculeChainsSequence LengthOrganismDetailsImage
COLICIN E7 IMMUNITY PROTEINA94Escherichia coliMutation(s): 0 
Gene Names: immceiE7
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
Protein Feature View
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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

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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