This book reviews the chemical regulatory and physiological mechanisms of protein arginine
and lysine methyltransferases as well as nucleic acid methylations and methylating enzymes.
Protein and nucleic acid methylation play key and diverse roles in cellular signalling and
regulating macromolecular cell functions.Protein arginine and lysine methyltransferases are the
predominant enzymes that catalyse S-adenosylmethionine (SAM)-dependent methylation of protein
substrates. These enzymes catalyse a nucleophilic substitution of a methyl group to an arginine
or lysine side chain nitrogen (N) atom. Cells also have additional protein methyltransferases
which target other amino acids in peptidyl side chains or N-termini and C-termini such as
glutamate glutamine and histidine. All these protein methyltransferases use a similar
mechanism. In contrast nucleic acids (DNA and RNA) are substrates for methylating enzymes
which employ various chemical mechanisms to methylate nucleosidesat nitrogen (N) oxygen (O)
and carbon (C) atoms. This book illustrates how thanks to there ability to expand their
repertoire of functions to the modified substrates protein and nucleic acid methylation
processes play a key role in cells.
