The DNA and S-adenosylmethionine-binding regions of EcoDam and related methyltransferases.
Previous comparison of the amino acid sequences of the GATC-methylating Escherichia coli Dam methyltransferase (MTase) with those of other adenine MTases (M.EcoRV, M.DpnII and T4Dam) localized four conserved regions. Regions III and IV have similarities with many other MTases. The sequence DPPY (or NPPY) is always present in region IV. It was suggested to be the AdoMet binding site. Publication of the nucleotide and amino acid sequences of M.CviBIII, M.DpnA and MutH give further credence to this assignment: M.DpnA, which also methylates GATC, has strong similarities with regions III and IV; M.CviBIII, a cytosine methylase, has a characteristic NPPY sequence in region IV, and only limited resemblance in region III; MutH, the GATC-specific endonuclease in DNA mismatch repair, has significant similarities uniquely in region III. The presently available evidence suggests that region III is the GAT(C) binding site and region IV is the AdoMet binding site. This hypothesis is strengthened by recent genetic findings.
Guschlbauer
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Département de Biologie, Centre d'Etudes Nucléaires de Saclay, Gif-sur-Yvette, France.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D015254:DNA Modification Methylases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004706:Endodeoxyribonucleases / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D012436:S-Adenosylmethionine / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012436:S-Adenosylmethionine; D015254:DNA Modification Methylases; D008780:Methyltransferases; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C499294:dam protein, E coli; D004706:Endodeoxyribonucleases; C059682:methyl-directed mismatch repair protein, E coli; D045643:DNA Repair Enzymes