Abstract
Mechanism-based inhibitors of enzymes, which mimic reactive intermediates in the reaction pathway, have been deployed extensively in the analysis of metabolic pathways and as candidate drugs. The inhibition of cytosine-[C5]-specific DNA methyltransferases (C5 MTases) by oligodeoxynucleotides containing 5-azadeoxycytidine (AzadC) and 5-fluorodeoxycytidine (FdC) provides a well-documented example of mechanism-based inhibition of enzymes central to nucleic acid metabolism. Here, we describe the interaction between the C5 MTase from Haemophilus haemolyticus (M.Hha I) and an oligodeoxynucleotide duplex containing 2-H pyrimidinone, an analogue often referred to as zebularine and known to give rise to high-affinity complexes with MTases. X-ray crystallography has demonstrated the formation of a covalent bond between M.Hha I and the 2-H pyrimidinone-containing oligodeoxynucleotide. This observation enables a comparison between the mechanisms of action of 2-H pyrimidinone with other mechanism- based inhibitors such as FdC. This novel complex provides a molecular explanation for the mechanism of action of the anti-cancer drug zebularine.
Original language | English (US) |
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Pages (from-to) | 591-599 |
Number of pages | 9 |
Journal | Journal of Molecular Biology |
Volume | 321 |
Issue number | 4 |
DOIs | |
State | Published - 2002 |
Externally published | Yes |
Keywords
- Base flipping
- DNA methylation
- DNA methyltransferase
- M.Hha I
- Zebularine
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology