>TIGR00452 TIGR00452 methyltransferase, putative; InterPro: IPR010017 Methyl transfer from the ubiquitous S-adenosyl-L-methionine (AdoMet) to either nitrogen, oxygen or carbon atoms is frequently employed in diverse organisms ranging from bacteria to plants and mammals. The reaction is catalyzed by methyltransferases (Mtases) and modifies DNA, RNA, proteins and small molecules, such as catechol for regulatory purposes. The various aspects of the role of DNA methylation in prokaryotic restriction-modification systems and in a number of cellular processes in eukaryotes including gene regulation and differentiation is well documented. Three classes of DNA Mtases transfer the methyl group from AdoMet to the target base to form either N-6-methyladenine, or N-4-methylcytosine, or C-5- methylcytosine. In C-5-cytosine Mtases, ten conserved motifs are arranged in the same order . Motif I (a glycine-rich or closely related consensus sequence; FAGxGG in M.HhaI ), shared by other AdoMet-Mtases , is part of the cofactor binding site and motif IV (PCQ) is part of the catalytic site. In contrast, sequence comparison among N-6-adenine and N-4-cytosine Mtases indicated two of the conserved segments , although more conserved segments may be present. One of them corresponds to motif I in C-5-cytosine Mtases, and the other is named (D/N/S)PP(Y/F). Crystal structures are known for a number of Mtases , , , . The cofactor binding sites are almost identical and the essential catalytic amino acids coincide. The comparable protein folding and the existence of equivalent amino acids in similar secondary and tertiary positions indicate that many (if not all) AdoMet-Mtases have a common catalytic domain structure. This permits tertiary structure prediction of other DNA, RNA, protein, and small-molecule AdoMet-Mtases from their amino acid sequences . This is a set of proteobacterial proteins, which have homology in their central region to a large number of methyltransferases active on a variety of substrates. .

Probab=93.57  E-value=0.086  Score=31.49  Aligned_cols=57  Identities=21%  Similarity=0.451  Sum_probs=41.8

Q ss_pred             HHHHHHHCCCCCCCEEEEECCCCCHHHHHHHHCCCCEEEEECCCCCC---HHHHHHHHHH
Q ss_conf             99999971989998799975898823467750235259984255430---3688787532
Q gi|254780398|r   36 LKKIAESSGSLDGITVIEIGAGPGNLTQMLLTLGARKVIVIEKDQQF---FPILKDISSQ   92 (284)
Q Consensus        36 ~~~iv~~~~~~~~~~VlEIGpG~G~LT~~Ll~~~~~~v~aiEiD~~~---~~~l~~~~~~   92 (284)
T Consensus       110 WDR~l~~~~pL~~~~i~DVGC~~GY~~~~M~~~Gak~~VG~DP~~L~~~QFE~~~~ll~~  169 (316)
T TIGR00452       110 WDRVLPHLSPLKGRTILDVGCGSGYHLWRMLGEGAKLLVGIDPTELFLCQFEAVRKLLDN  169 (316)
T ss_pred             HHHHCCCCCCCCCCEEEEECCCCHHHHHHHHHCCCCEEEECCHHHHHHHHHHHHHHHHCC
T ss_conf             554312466545777898336870688977620782787436578999999999987242