Noun
adenosyl (plural adenosyls)
(biochemistry, especially in combination) The univalent radical derived from adenosine
SAM is composed of an adenosyl molecule (via 5' carbon) attached to the sulfur of methionine, therefore making it a sulfonium cation (i.e. three substituents and positive charge). Source: Internet
These enzymes methylate only one strand of the DNA, at the N-6 position of adenosyl residues, so newly replicated DNA will have only one strand methylated, which is sufficient to protect against restriction. Source: Internet