Establishment and maintenance of DNA methylation patterns in mammals.

In mammals, CpG methylation patterns are established and maintained during development by the Dnmt1 and Dnmt3 families of DNA methyltransferases. These enzymes share conserved catalytic motifs in their C-terminal regions, but have unique N-terminal regulatory domains. Studies over the past several years have shed light on the molecular mechanisms by which DNA methylation patterns are regulated. This review focuses on recent advances in defining the functional domains of DNA methyltransferases and identifying interacting proteins that may contribute to the functional specializations of these enzymes.