2JUB

Solution structure of IPI*


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Restriction endonuclease inhibitor IPI* of bacteriophage T4: a novel structure for a dedicated target.

Rifat, D.Wright, N.T.Varney, K.M.Weber, D.J.Black, L.W.

(2008) J.Mol.Biol. 375: 720-734

  • DOI: 10.1016/j.jmb.2007.10.064

  • PubMed Abstract: 
  • Phage T4 protects its DNA from the two-gene-encoded gmrS/gmrD (glucose-modified hydroxymethylcytosine restriction endonuclease) CT of pathogenic Escherichia coli, CT596, by injecting several hundred copies of the 76-amino-acid-residue nuclease inhibi ...

    Phage T4 protects its DNA from the two-gene-encoded gmrS/gmrD (glucose-modified hydroxymethylcytosine restriction endonuclease) CT of pathogenic Escherichia coli, CT596, by injecting several hundred copies of the 76-amino-acid-residue nuclease inhibitor, IPI*, into the infected host. Here, the three-dimensional solution structure of mature IPI* is reported as determined by nuclear magnetic resonance techniques using 1290 experimental nuclear Overhauser effect and dipolar coupling constraints ( approximately 17 constraints per residue). Close examination of this oblate-shaped protein structure reveals a novel fold consisting of two small beta-sheets (beta1: B1 and B2; beta2: B3-B5) flanked at the N- and C-termini by alpha-helices (H1 and H2). Such a fold is very compact in shape and allows ejection of IPI* through the narrow 30-A portal and tail tube apertures of the virion without unfolding. Structural and dynamic measurements identify an exposed hydrophobic knob that is a putative gmrS/gmrD-binding site. A single gene from the uropathogenic E. coli UT189, which codes for a gmrS/gmrD-like UT fusion enzyme (with approximately 90% identity to the heterodimeric CT enzyme), has evolved IPI* inhibitor immunity. Analysis of the gmrS/gmrD restriction endonuclease enzyme family and its IPI* family phage antagonists reveals an evolutionary pathway that has elaborated a surprisingly diverse and specifically fitted set of coevolving attack and defense structures.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 North Greene Street, Baltimore, MD 21201-1503, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Internal protein I
A
76Enterobacteria phage T4Gene Names: ipi1 (ipi)
Find proteins for P03718 (Enterobacteria phage T4)
Go to UniProtKB:  P03718
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 
  • Olderado: 2JUB Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-12-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance