Overview for MACiE Entry M0046

Version history

General Information

EC Number: (A member of the Transferases, Transferring one-carbon groups, Methyltransferases)

Enzyme Name: site-specific DNA-methyltransferase

Biological Species: Thermus aquaticus (Bacteria)

Catalytic Chain UniprotKB Accession Codes:

  • P14385 - Modification methylase TaqI

Representative PDB Code: 2adm - ADENINE-N6-DNA-METHYLTRANSFERASE TAQI (Resolution = 2.60 Å).

Catalytic CATH Codes:

"Other" CATH Codes:

  • - Adenine-n6-DNA-methyltransferase Taqi, Chain A, domain 2

Display structure information

Overall Reaction:

Image of S-adenosyl-L-methionine

Image of DNA adenine

right arrow

Image of proton

Image of DNA 6-methylaminopurine

Image of S-adenosyl-L-homocysteine

DNA adenine
DNA 6-methylaminopurine

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Stepwise Description of the Reaction

Step 1The 6-amino group of DNA adenine initiates a nucleophilic attack upon the methyl carbon of S-adenosyl-L-methionine in a substitution reaction.
Step 2Water deprotonates the 6-amino group of the DNA methyladenine product.

View similar reactions (composite manual annotation)

Catalytic Residues Involved

Type Number Chain Location of Function
Asn 105 A Side Chain
Pro 106 A Main Chain Carbonyl
Tyr 108 A Side Chain


  1. Z. E. R. Newby et al. (2002), Proc. Natl Acad. Sci. USA, 99, 7922-7927. A theoretical examination of the factors controlling the catalytic efficiency of the DNA-(adenine-N6)-methyltransferase from Thermus aquaticus.
    Medline: 12060740
  2. K. Goedecke et al. (2001), Nat. Struct. Biol., 8, 121-125. Structure of the N6-adenine DNA methyltransferase M.TaqI in complex with DNA and a cofactor analog.
    Medline: 11175899
  3. H. Pues et al. (1999), Biochemistry, 38, 1426-1434. Functional roles of the conserved aromatic amino acid residues at position 108 (motif IV) and position 196 (motif VIII) in base flipping and catalysis by the N6-adenine DNA methyltransferase from Thermus aquaticus.
    Medline: 9931007

Homologue information for M0046 (2adm)

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
M0293 cytosine-specific methyltransferase HhaI

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

GOA logo
nucleic acid binding (molecular function)
DNA binding (molecular function)
catalytic activity (molecular function)
DNA modification (biological process)
methyltransferase activity (molecular function)
site-specific DNA-methyltransferase (adenine-specific) activity (molecular function)
DNA restriction-modification system (biological process)
transferase activity (molecular function)
methylation (biological process)
DNA methylation on adenine (biological process)