N6-Adenine DNA-methyltransferase in wheat seedlings

AbstractThe N6-adenine DNA-methyltransferase was isolated from the vacuolar vesicle fraction of wheat coleoptiles. In the presence of S-adenosyl-L-methionine the enzyme de novo methylates the first adenine residue in the TGATCA sequence in the single- or double-stranded DNA substrates but it prefers single-stranded structures. Wheat adenine DNA-methyltransferase (wadmtase) is a Mg2+- or Ca2+-dependent enzyme with a maximum activity at pH 7.5–8.0. Wadmtase seems to be responsible for mitochondrial DNA modification that might be involved in the regulation of replication of mitochondria in plants