Enzymes that are part of the restriction-modification systems. They are responsible for producing a species-characteristic methylation pattern, on either adenine or cytosine residues, in a specific short base sequence in the host cell's own DNA. This methylated sequence will occur many times in the host-cell DNA and remain intact for the lifetime of the cell. Any DNA from another species which gains entry into a living cell and lacks the characteristic methylation pattern will be recognized by the restriction endonucleases of similar specificity and destroyed by cleavage. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms.

Descriptor ID	D015254
MeSH Number(s)	D08.811.150.240 D08.811.913.555.500.350
Concept/Terms	DNA Modification Methylases DNA Modification Methylases Methylases, DNA Modification Modification Methylases, DNA Modification Methylases Methylases, Modification DNA Modification Methyltransferases Methyltransferases, DNA Modification Modification Methyltransferases, DNA

Below are MeSH descriptors whose meaning is more general than "DNA Modification Methylases".

Below are MeSH descriptors whose meaning is related to "DNA Modification Methylases".

Below are MeSH descriptors whose meaning is more specific than "DNA Modification Methylases".