Cloning, sequence analysis and heterologous expression of the DNA adenine-(N(6)) methyltransferase from the human pathogen Actinobacillus actinomycetemcomitans

FEMS Microbiol Lett. 2001 Feb 20;195(2):223-9. doi: 10.1111/j.1574-6968.2001.tb10525.x.


We cloned and sequenced the DNA adenine-N(6) methyltransferase gene of the human pathogen Actinobacillus actinomycetemcomitans (M.AacDAM). Restriction digestion shows that the enzyme methylates adenine in the sequence GATC. Expression of the enzyme in a DAM(-) background shows in vivo activity. A PSI-BLAST search revealed that M.AacDAM is most related to M.HindIV, M.EcoDAM, M.StyDAM, and M.SmaII. The ClustalW alignment shows highly conserved regions in the enzyme characteristic for type a MTases. Phylogenetic tree analysis shows a cluster of enzymes recognizing the sequence GATC, within a branch of orphan MTases harboring M.AacDAM. The cloning and sequencing of this first methyltransferase gene described for A. actinomycetemcomitans open the path for studies on the potential regulatory impact of DNA methylation on gene regulation and virulence in this organism.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenine / metabolism
  • Aggregatibacter actinomycetemcomitans / enzymology*
  • Aggregatibacter actinomycetemcomitans / genetics
  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Conserved Sequence
  • DNA Restriction Enzymes / metabolism
  • Escherichia coli / genetics
  • Genes, Bacterial
  • Humans
  • Methylation
  • Molecular Sequence Data
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Site-Specific DNA-Methyltransferase (Adenine-Specific) / chemistry
  • Site-Specific DNA-Methyltransferase (Adenine-Specific) / genetics*
  • Site-Specific DNA-Methyltransferase (Adenine-Specific) / metabolism*


  • Recombinant Proteins
  • Site-Specific DNA-Methyltransferase (Adenine-Specific)
  • DNA Restriction Enzymes
  • Adenine