>TIGR00571 dam DNA adenine methylase; InterPro: IPR012326 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 IPR001525 from INTERPRO). 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 (2.1.1.72 from EC) (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 recognize 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 a DPPY motif (CM II) occuring after the FxGxG motif (CM I) are designated D12 class N6-adenine MTases.; GO: 0009007 site-specific DNA-methyltransferase (adenine-specific) activity, 0006306 DNA methylation.

Probab=93.72  E-value=0.018  Score=35.58  Aligned_cols=60  Identities=17%  Similarity=0.301  Sum_probs=29.3

Q ss_pred             CHHHHHHHHHHHHHHCCCCCCCCCCCCHHHH----H---------CCHH-HHHHHHHHCCCC-CCCEEEEEECCC
Q ss_conf             0022344566542100344443101513431----0---------0028-889888744888-897499998177
Q gi|254780405|r   99 NCNIFFRDVLRLGKIGNISPFQLVYLDPPYG----Q---------GLAQ-QALAIIDKEGWL-EPNALVIIEEYA  158 (189)
Q Consensus        99 ~~~ii~~D~~~~~~~~~~~~fDiIf~DPPY~----~---------~~~~-~~l~~l~~~~~L-~~~gliiiE~~~  158 (189)
T Consensus       202 n~~f~c~~F~~~~~~~~~~sP~fVY~DPPY~p~~~~~~Ft~Y~~~~F~~~~q~~La~~~~~l~~~rg~~~~~SN~  276 (327)
T TIGR00571       202 NTTFLCGSFEKILEMVDRDSPDFVYLDPPYLPLSATANFTGYHKNGFDEDEQKRLANFCKSLSDERGIKFLLSNS  276 (327)
T ss_pred             CCEEEECCHHHHHHHCCCCCCCEEEECCCCCCCCCCEEECCCCCCCCCHHHHHHHHHHHHHHHHHCCCEEEEECC
T ss_conf             815752566788623037888378757789985232131156557888899999999998754530660477456