| Primary Identifier | IPR012263 | Type | Family |
| Short Name | M_m6A_EcoRV |
| 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. They include enzymes are found in bacterial restriction-modification systems, as well as solitary enzymes that do not have a restriction enzyme counterpart [].Proteins in this entry are homologous to Dam methyltransferase () from Escherichia coli which recognises the sequence GATC and methylates the adenine moeity. This protein is not part of a restriction modification system and its activity influences cellular functions such as gene transcription, DNA mismatch repair, initiation of chromosome replication and nucleoid structure []. It is dispensible in E. coli, but has been shown to be required for viability in Yersinia and Vibrio species, virulence in Salmonella, and replication in some bacteriophages. Dam methyltransferase consists of a seven-stranded beta sheet sandwiched between two layers of alpha helices [, ]. The beta sheet contains the catalytic domain, while the target recognition domain is composed of five alpha helices and a beta hairpin. The methyl donor binds to a region of the beta sheet, surrounded by conserved residues, which is next to a narrow surface pocket thought to contain the active site. |
