1AF5 | pdb_00001af5

GROUP I MOBILE INTRON ENDONUCLEASE

• PDB DOI: https://doi.org/10.2210/pdb1AF5/pdb

• Classification: ENDONUCLEASE
• Organism(s): Chlamydomonas reinhardtii
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 1997-03-21 Released: 1997-07-23 
• Deposition Author(s): Heath, P.J., Stephens, K.M., Monnat Junior, R.J., Stoddard, B.L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.00 Å
• R-Value Free: 
  0.373 (Depositor) 
• R-Value Work: 
  0.248 (Depositor) 
• R-Value Observed: 
  0.248 (Depositor) 

Literature

The structure of I-Crel, a group I intron-encoded homing endonuclease.

Heath, P.J., Stephens, K.M., Monnat Jr., R.J., Stoddard, B.L.

(1997) Nat Struct Biol 4: 468-476

• PubMed: 9187655 
• DOI: https://doi.org/10.1038/nsb0697-468
• Primary Citation of Related Structures:  
  1AF5


• PubMed Abstract: 
  

  The structure of I-Crel provides the first view of a protein encoded by a gene within an intron. This endonuclease recognizes a long DNA site approximately 20 base pairs in length and facilitates the lateral transfer of that intron. The protein exhibits a DNA-binding surface consisting of four antiparallel beta-strands that form a 20 A wide groove which is over 70 A long. The architecture of this fold is different from that of the TATA binding protein, TBP, which also contains an antiparallel beta-saddle. The conserved LAGLIDADG motif, which is found in many mobile intron endonucleases, maturases and inteins, forms a novel helical interface and contributes essential residues to the active site.

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Organizational Affiliation: 

Fred Hutchinson Cancer Research Center, Division of Basic Sciences, Seattle, Washington 98104, USA.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 15.55 kDa 
• Atom Count: 1,037 
• Modelled Residue Count: 126 
• Deposited Residue Count: 135 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
I-CREI	A	135	Chlamydomonas reinhardtii	Mutation(s): 1  EC: 3.1
UniProt
Find proteins for P05725 (Chlamydomonas reinhardtii) Explore P05725  Go to UniProtKB:  P05725

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.00 Å
• R-Value Free:  0.373 (Depositor) 
• R-Value Work:  0.248 (Depositor) 
• R-Value Observed: 0.248 (Depositor) 

Space Group: P 3 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 78.2	α = 90
b = 78.2	β = 90
c = 67.4	γ = 120

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1997-07-23 
Deposition Author(s): Heath, P.J., Stephens, K.M., Monnat Junior, R.J., Stoddard, B.L.

Revision History  

• Version 1.0: 1997-07-23
  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: 2021-11-03
  Changes: Database references, Other
• Version 1.4: 2024-02-07
  Changes: Data collection