InterPro : IPR002296

Name  N6 adenine-specific DNA methyltransferase, N12 class Short Name  N12N6_MeTrfase
Type  Family Description  In prokaryotes, the major role of DNA methylation is to protect host DNA against degradation by restriction enzymes. There are 2 major classes of DNA methyltransferase that differ in the nature of the modifications they effect. The members of one class (C-MTases) methylate a ring carbon and form C5-methylcytosine (see ). Members of the second class (N-MTases) methylate exocyclic nitrogens and form either N4-methylcytosine (N4-MTases) or N6-methyladenine (N6-MTases). Both classes of MTase utilise the cofactor S-adenosyl-L-methionine (SAM) as the methyl donor and are active as monomeric enzymes [].N-6 adenine-specific DNA methylases () (A-Mtase) are enzymes that specifically methylate the amino group at the C-6 position of adenines in DNA. Such enzymes are found in the three existing types of bacterial restriction-modification systems (in type I system the A-Mtase is the product of the hsdM gene, and in type III it is the product of the mod gene). All of these enzymes recognise a specific sequence in DNA and methylate an adenine in that sequence. It has been shown [, , , ]that A-Mtases contain a conserved motif Asp/Asn-Pro-Pro-Tyr/Phe in their N-terminal section, this conserved region could be involved in substrate binding or in the catalytic activity. The structure of N6-MTase TaqI (M.TaqI) has been resolved to 2.4 A []. The molecule folds into 2 domains, an N-terminal catalytic domain, which contains the catalytic and cofactor binding sites, and comprises a central 9-stranded beta-sheet, surrounded by 5 helices; and a C-terminal DNA recognition domain, which is formed by 4 small beta-sheets and 8 alpha-helices. The N- and C-terminal domains form a cleft that accommodates the DNA substrate. A classification of N-MTases has been proposed, based on conserved motif (CM) arrangements []. According to this classification, N6-MTases that have an NPPY motif (CM II) occuring after the FxGxG motif (CM I) are designated N12 class N6-adenine MTases.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



2 Child Features

Id Name Short Name Type
IPR004546 Restriction endonuclease, type I, HsdM Restrct_endonuc_typeI_HsdM Family
IPR021188 N6 adenine-specific DNA methyltransferase, TaqI class N6_DNA_MeTrfase_TaqI Family

4 Contains

Id Name Short Name Type
IPR022749 N6 adenine-specific DNA methyltransferase, N-terminal domain D12N6_MeTrfase_N Domain
IPR002052 DNA methylase, N-6 adenine-specific, conserved site DNA_methylase_N6_adenine_CS Conserved_site
IPR003356 DNA methylase, adenine-specific DNA_methylase_A-5 Domain
IPR011639 Restriction modification methylase Eco57I RM_methylase_Eco57I Domain

0 Found In

0 Parent Features

6 Publications

First Author Title Year Journal Volume Pages
Labahn J Three-dimensional structure of the adenine-specific DNA methyltransferase M.Taq I in complex with the cofactor S-adenosylmethionine. 1994 Proc Natl Acad Sci U S A 91 10957-61
Cheng X Structure and function of DNA methyltransferases. 1995 Annu Rev Biophys Biomol Struct 24 293-318
Narva KE The amino acid sequence of the eukaryotic DNA [N6-adenine]methyltransferase, M.CviBIII, has regions of similarity with the prokaryotic isoschizomer M.TaqI and other DNA [N6-adenine] methyltransferases. 1988 Gene 74 253-9
Timinskas A Sequence motifs characteristic for DNA [cytosine-N4] and DNA [adenine-N6] methyltransferases. Classification of all DNA methyltransferases. 1995 Gene 157 3-11
Loenen WA Organization and sequence of the hsd genes of Escherichia coli K-12. 1987 J Mol Biol 198 159-70
Lauster R Evolution of type II DNA methyltransferases. A gene duplication model. 1989 J Mol Biol 206 313-21

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)