[Prokaryotic DNA methyltransferases: the structure and the mechanism of interaction with DNA].
The review considers current views on the function of DNA methyltransferases (MTases) that belong to prokaryotic type II restriction-modification systems. A commonly accepted classification of MTases is described along with their primary and tertiary structures and molecular mechanisms of their specific interaction with DNA (including methylation). MTase inhibitors are also considered. Special emphasis is placed on the flipping of the target heterocyclic base out of the double helix and on the methods employed in its analysis. Base flipping is a fundamentally new type of DNA conformational changes and is also of importance in the case of other DNA-operating enzymes. MTases show unique sequence homology, and are similar in structure of functional centers and in the mechanism of methylation. These data contribute to the understanding of the general biological significance of methylation, since prokaryotic and eukaryotic MTases are structurally and functionally similar.
Gromova
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ES
Chemical Department, Moscow State University, Moscow, 119992 Russia. gromova@genebee.msu.ru
Khoroshaev
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AV
D002384:Catalysis; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D008958:Models, Molecular; D011387:Prokaryotic Cells / Q000201:enzymology*; D011487:Protein Conformation; D013379:Substrate Specificity
D004791:Enzyme Inhibitors; D015254:DNA Modification Methylases