N6-methyladenine: the other methylated base of DNA
Article first published online: 14 FEB 2006
Copyright © 2006 Wiley Periodicals, Inc.
Volume 28, Issue 3, pages 309–315, March 2006
How to Cite
Ratel, D., Ravanat, J.-L., Berger, F. and Wion, D. (2006), N6-methyladenine: the other methylated base of DNA. Bioessays, 28: 309–315. doi: 10.1002/bies.20342
- Issue published online: 14 FEB 2006
- Article first published online: 14 FEB 2006
- DW is supported by the Fondation Jérôme Lejeune
- U318 is supported by LNCC and CIT
Contrary to mammalian DNA, which is thought to contain only 5-methylcytosine (m5C), bacterial DNA contains two additional methylated bases, namely N6-methyladenine (m6A), and N4-methylcytosine (m4C). However, if the main function of m5C and m4C in bacteria is protection against restriction enzymes, the roles of m6A are multiple and include, for example, the regulation of virulence and the control of many bacterial DNA functions such as the replication, repair, expression and transposition of DNA. Interestingly, even if adenine methylation is usually considered a bacterial DNA feature, the presence of m6A has been found in protist and plant DNAs. Furthermore, indirect evidence suggests the presence of m6A in mammal DNA, raising the possibility that this base has remained undetected due to the low sensitivity of the analytical methods used. This highlights the importance of considering m6A as the sixth element of DNA. BioEssays 28: 309–315, 2006. © 2006 Wiley Periodicals, Inc.