7CEI

THE ENDONUCLEASE DOMAIN OF COLICIN E7 IN COMPLEX WITH ITS INHIBITOR IM7 PROTEIN

• PDB DOI:  https://doi.org/10.2210/pdb7CEI/pdb

• Classification: IMMUNE SYSTEM
• Organism(s): Escherichia coli str. K-12 substr. W3110
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1998-09-17 Released: 1999-09-17 
• Deposition Author(s): Ko, T.P., Liao, C.C., Ku, W.Y., Chak, K.F., Yuan, H.S.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Free: 0.270 
• R-Value Work: 0.203 
• R-Value Observed: 0.203 

Literature

The crystal structure of the DNase domain of colicin E7 in complex with its inhibitor Im7 protein.

Ko, T.P., Liao, C.C., Ku, W.Y., Chak, K.F., Yuan, H.S.

(1999) Structure 7: 91-102

• PubMed: 10368275 
• DOI: https://doi.org/10.1016/s0969-2126(99)80012-4
• Primary Citation of Related Structures:  
  7CEI


• PubMed Abstract: 
  

Colicin E7 (ColE7) is one of the bacterial toxins classified as a DNase-type E-group colicin. The cytotoxic activity of a colicin in a colicin-producing cell can be counteracted by binding of the colicin to a highly specific immunity protein. This biological event is a good model system for the investigation of protein recognition.

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Related Citations: 

• 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

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Organizational Affiliation: 

Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 11529, Republic of China.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 33.44 kDa 
• Atom Count: 1,887 
• Modelled Residue Count: 214 
• Deposited Residue Count: 293 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (COLICIN E7 IMMUNITY PROTEIN)	A	87	Escherichia coli str. K-12 substr. W3110	Mutation(s): 0  Gene Names: ceiE7
UniProt
Find proteins for Q03708 (Escherichia coli) Explore Q03708  Go to UniProtKB:  Q03708

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (COLICIN E7 IMMUNITY PROTEIN)	B	206	Escherichia coli str. K-12 substr. W3110	Mutation(s): 0  EC: 3.1
UniProt
Find proteins for Q47112 (Escherichia coli) Explore Q47112  Go to UniProtKB:  Q47112

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	C [auth B]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Free: 0.270 
• R-Value Work: 0.203 
• R-Value Observed: 0.203 
• Space Group: I 2 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 65.44	α = 90
b = 76.02	β = 90
c = 119.99	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1999-09-17 
Deposition Author(s): Ko, T.P., Liao, C.C., Ku, W.Y., Chak, K.F., Yuan, H.S.

Revision History  

• Version 1.0: 1999-09-17
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Source and taxonomy, Version format compliance
• Version 1.3: 2023-09-20
  Changes: Data collection, Database references, Derived calculations, Refinement description