DNA methylation can occur in either the cytosine or adenine bases, cytosine methylation is generally found in eukaryotic cells whilst both but mainly adenine methylation can be found in bacteria. DNA methylation results in the addition of a methyl group to carbon five in the respective base by the enzyme DNA methylase, so using the example of cytosine when methylated it becomes 5-methylcystosine.
The effect of DNA methylation is that those areas of the DNA aren’t sequenced and therefore the affected genes aren’t expressed proceeding to show phenotypic change.
- ↑ D. T. Meštrović, "DNA Methylation in Bacteria," News Medical Life Sciences and Medicine, 10 09 2014. [Online]. Available: http://www.news-medical.net/health/DNA-Methylation-in-Bacteria.aspx. [Accessed 23 11 2015].
- ↑ D. L. a. E. W. Jones, "Genetics Analysis of Genes and Genomes 7th Edition," in Epigenetic Mechanisms of Transcriptional Regulation, London, Jones and Bartlett Publishers, 20009, p. 411.