Chemicals and Drugs

DNA Modification Methylases

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.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

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.

MeSH Record

Classification

Broader headings

Narrower headings

Related Concepts

Knowledge Graph

Loading graph…

Drag nodes to rearrange; hover to trace links; click a node to open its page.

MeSH Record

Synonyms

7 entry terms
  • DNA Modification Methyltransferases
  • Modification Methylases
  • Methylases, DNA Modification
  • Methylases, Modification
  • Methyltransferases, DNA Modification
  • Modification Methylases, DNA
  • Modification Methyltransferases, DNA

MeSH Record

Aspects Covered

29 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, analysis, antagonists & inhibitors, biosynthesis, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, deficiency, drug effects, economics, genetics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, physiology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, ultrastructure, urine.

MeSH Record

History Note

1989

MeSH Record

Previous Indexing

  • DNA (Cytosine-5-)-Methyltransferase (1975-1988)
  • Methyltransferases (1971-1988)

MeSH Hierarchy

Tree Numbers

  1. D08.811w.150w.240
  2. D08.811w.913w.555.500w.350

AMA Style

References

  1. National Library of Medicine. DNA Modification Methylases. Medical Subject Headings (MeSH). 2026. Unique ID D015254. http://id.nlm.nih.gov/mesh/2026/D015254
  2. DNA Modification Methylases. In: Wikidata. https://www.wikidata.org/wiki/Q24722329