Overview for MACiE Entry M0160

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General Information

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

Enzyme Name: exodeoxyribonuclease III

Biological Species: Escherichia coli (Bacteria)

Catalytic Chain UniprotKB Accession Codes:

  • P09030 - Exodeoxyribonuclease III

Representative PDB Code: 1ako - EXONUCLEASE III FROM ESCHERICHIA COLI (Resolution = 1.70 Å).

Catalytic CATH Codes:

Display structure information

Overall Reaction:

Image of DNA

Image of water

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Image of nucleoside 5'-phosphate

Image of DNA 3'-hydroxyl

nucleoside 5'-phosphate
DNA 3'-hydroxyl

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Stepwise Description of the Reaction

Step 1His259 deprotonates water, which attacks the phosphate of DNA in a nucleophilic substitution that results in the cleavage of the phosphate bond, the 5' end of the DNA molecule reprotonates from Asp151.
Step 2Asp151 deprotonates His259.

View similar reactions (composite manual annotation)

Catalytic Residues Involved

Type Number Chain Location of Function
Asn 7 A Side Chain
Asp 151 A Side Chain
Asn 153 A Side Chain
Asp 229 A Side Chain
His 259 A Side Chain

Metal Cofactors for M0160

Type Het group Number Chain
magnesium MG(not in PDB) 1 x Overview


  1. C. B. Black et al. (1997), Eur. J. Biochem., 243, 684-689. Inert chromium and cobalt complexes as probes of magnesium-dependent enzymes. Evaluation of the mechanistic role of the essential metal cofactor in Escherichia coli exonuclease III.
    Medline: 9057832
  2. C. D. Mol et al. (1995), Nature, 374, 381-386. Structure and function of the multifunctional DNA-repair enzyme exonuclease III.
    Medline: 7885481

Homologue information for M0160 (1ako)

CSA Homologues

MACiE Homologues (within the PDB)

MACiE Homologues (within UniprotKB/SwissProt)

Entries with at least one Catalytic CATH code in common (different mechanisms):

MACiE Entry Enzyme Name
EC Number
PDB code CATH code Composite
Reaction Similarity
Catalytic Machinery
M0041 deoxyribonuclease I

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
Link to EzCatDB

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DNA binding (molecular function)
nuclease activity (molecular function)
endonuclease activity (molecular function)
intracellular (cellular component)
DNA repair (biological process)