Is the HemK family of putative S-adenosylmethionine-dependent methyltransferases a "missing" zeta subfamily of adenine methyltransferases? A hypothesis.
Previous comparative studies revealed close similarity among various groups of S-adenosyl-L-methionine (AdoMet)-dependent methyltransferases (MTases), indicating their common evolutionary origin. We present evidence for a remarkable similarity between the sequence and predicted structure of HemK (a widespread family of putative proteins encoded in genomes from bacteria to humans) and the catalytic domain of the gamma-subfamily of adenine-specific DNA MTases (N6mA MTases). We predict the structure and function of the putative catalytic domain of HemK proteins and speculate that the target-recognizing function may be conferred by the N-terminal variable region.
Bujnicki
J M
JM
Molecular Biology Research Program, Henry Ford Health System, Detroit, Michigan 48202, USA. iamb@ibbrain.ibb.waw.pl
Radlinska
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins; D006801:Humans; D008780:Methyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D011496:Protein Methyltransferases; D016415:Sequence Alignment; D017421:Sequence Analysis; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000145:classification / Q000235:genetics*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008780:Methyltransferases; D011496:Protein Methyltransferases; C073145:S-adenosylmethionine-dependent phosphate methyltransferase; C092404:prmC protein, E coli; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)