1M5X

Crystal structure of the homing endonuclease I-MsoI bound to its DNA substrate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.219 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Flexible DNA Target Site Recognition by Divergent Homing Endonuclease Isoschizomers I-CreI and I-MsoI

Chevalier, B.Turmel, M.Lemieux, C.Monnat, R.J.Stoddard, B.L.

(2003) J.Mol.Biol. 329: 253-269

  • Primary Citation of Related Structures:  1N3E, 1N3F

  • PubMed Abstract: 
  • Homing endonucleases are highly specific catalysts of DNA strand breaks that induce the transposition of mobile intervening sequences containing the endonuclease open reading frame. These enzymes recognize long DNA targets while tolerating individual ...

    Homing endonucleases are highly specific catalysts of DNA strand breaks that induce the transposition of mobile intervening sequences containing the endonuclease open reading frame. These enzymes recognize long DNA targets while tolerating individual sequence polymorphisms within those sites. Sequences of the homing endonucleases themselves diversify to a great extent after founding intron invasion events, generating highly divergent enzymes that recognize similar target sequences. Here, we visualize the mechanism of flexible DNA recognition and the pattern of structural divergence displayed by two homing endonuclease isoschizomers. We determined structures of I-CreI bound to two DNA target sites that differ at eight of 22 base-pairs, and the structure of an isoschizomer, I-MsoI, bound to a nearly identical DNA target site. This study illustrates several principles governing promiscuous base-pair recognition by DNA-binding proteins, and demonstrates that the isoschizomers display strikingly different protein/DNA contacts. The structures allow us to determine the information content at individual positions in the binding site as a function of the distribution of direct and water-mediated contacts to nucleotide bases, and provide an evolutionary snapshot of endonucleases at an early stage of divergence in their target specificity.


    Organizational Affiliation

    Division of Basic Sciences, Graduate Program in Molecular and Cellular Biology, University of Washington and the Fred Hutchinson Cancer Research Center, Seattle 98109, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
DNA endonuclease I-MsoI
A, B
170Monomastix sp. (strain OKE-1)Gene Names: orf170
Find proteins for C0JWR6 (Monomastix sp. (strain OKE-1))
Go to UniProtKB:  C0JWR6
Entity ID: 1
MoleculeChainsLengthOrganism
5'-D(*GP*CP*AP*GP*AP*AP*CP*GP*TP*CP*GP*TP*GP*AP*GP*AP*CP*AP*GP*TP*TP*CP*CP*G)-3'C24N/A
Entity ID: 2
MoleculeChainsLengthOrganism
5'-D(*CP*GP*GP*AP*AP*CP*TP*GP*TP*CP*TP*CP*AP*CP*GP*AP*CP*GP*TP*TP*CP*TP*GP*C)-3'D24N/A
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B, C
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.219 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 41.510α = 73.34
b = 42.210β = 73.17
c = 71.320γ = 71.09
Software Package:
Software NamePurpose
SCALEPACKdata scaling
EPMRphasing
CNSrefinement
HKL-2000data collection
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-06-03
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance