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Overview for MACiE Entry M0233

Version history

General Information

EC Number: 3.1.21.- (A member of the Hydrolases, Acting on ester bonds, Endodeoxyribonucleases producing 5'-phosphomonoesters)

Enzyme Name: DNA endonuclease I-CreI

Biological Species: Chlamydomonas reinhardtii (Green algae)

Catalytic Chain UniprotKB Accession Codes:

  • P05725 - DNA endonuclease I-CreI

Representative PDB Code: 1g9z - LAGLIDADG HOMING ENDONUCLEASE I-CREI / DNA PRODUCT COMPLEXWITH MAGNESIUM (Resolution = 1.80 Å).

Catalytic CATH Codes:

  • This enzyme has no catalytic CATH domains assigned

"Other" CATH Codes:

Display structure information

Overall Reaction:

Image of Double-stranded DNA

Image of Water

right arrow

Image of Doubly cleaved double-stranded DNA

Double-stranded DNA
C00434
CHEBI:4705
2 Water
C00001
CHEBI:15377
Doubly cleaved double-stranded DNA
X00120

Overall Comment: I-CreI exists as a homodimer and the active sites of the enzyme overlap. Mg901 binds to one subunit, Mg903 binds to the other and Mg902 is bound to both. Mg902 is involved in the hydrolysis of both strands of DNA while Mg901 is involved in the hydrolysis of one strand and Mg903 the other.


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Stepwise Description of the Reaction

Step 1Activated water, coordinated to Mg901, is the nucleophile for in-line attack on the scissile DNA phosphate. The transition state is trigonal bipyramidal. The 3'-hydroxyl leaving group coordinates to Mg902 and this favours its protonation by water.
Step 2Activated water, coordinated to Mg903, is the nucleophile for in-line attack on the scissile phosphate of the other DNA strand. The transition state is trigonal bipyramidal. The 3'-hydroxyl leaving group coordinates to Mg902 and this favours its protonation by water.

View similar reactions (composite manual annotation)


Catalytic Residues Involved

There are no catalytic residues associated with this reaction mechanism


Metal Cofactors for M0233

Type Het group Number Chain
magnesium MG 902 _ Overview
magnesium MG 901 _ Overview
magnesium MG 903 _ Overview

References

  1. B. Chevalier et al. (2004), Biochemistry, 43, 14015-14026. Metal-dependent DNA cleavage mechanism of the I-CreI LAGLIDADG homing endonuclease.
    Medline: 15518550
  2. B. S. Chevalier et al. (2001), Nat. Struct. Biol., 8, 312-316. The homing endonuclease I-CreI uses three metals, one of which is shared between the two active sites.
    Medline: 11276249

Homologue information for M0233 (1g9z)

MACiE Homologues (within the PDB)

MACiE Homologues (within UniprotKB/SwissProt)


Links to this entry in other databases

Link to EC-PDB-SUM Link to PDB-SUM Link to RCSB PDB Link to PDBe Link to CSA
Link to MetaCyc Link to KEGG Link to BRENDA Link to ExplorENZ

GOA logo
DNA binding (molecular function)
nuclease activity (molecular function)
endonuclease activity (molecular function)
intron homing (biological process)
chloroplast (cellular component)
plastid (cellular component)
hydrolase activity (molecular function)
metal ion binding (molecular function)
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