Product Catalog cover for Methylation, Ltd.

Product Catalog cover for Methylation, Ltd.

DNA methylation at CpG sites is an essential feature of gene regulation in higher eukarya [1-3]. Methylation of cytosine residues is correlated with silenced chromatin and there is strong evidence that inappropriate methylation can disrupt normal growth control circuits [2]. The process is mediated by enzymes called DNA methyltransferases (DNMTs) and a number of different DNMT isoforms have been identified, cloned and characterized [1]. DNMT isoforms fall into two broad groupings: 1) Maintenance activities which preferentially act on hemi-methylated DNA, and 2) De novo activities which initiate methylation on a unmethylated
DNA targets. DNMT1 is a maintenance enzyme that most likely targets replicative or nascent DNA. DNMT3 type isoforms appear to be de novo methyltransferases. Other DNMTs are now known to be active but have not been classified (DNMT2) while still other isoforms appear to possess key motifs of DNMT but lack sequences necessary for catalytic activity (DNMT3L).