Appendix 2: Databases of DNA Modifications
Kristian Rother, Grzegorz Papaj and Janusz M. Bujnicki
The most prominent source of information on prokaryotic DNA modifications is REBASE (http://rebase.neb.com/rebase/rebase.html), which exhaustively covers restriction endonucleases and DNA methyltransferases. As of September 2008, it contains entries for almost 4000 restriction endonucleases (most of which are from class II) and almost 1000 methyltransferases, whose functions have been studied experimentally. In addition, more than 3500 putative endonucleases and 6000 putative methyltransferases have been deposited in REBASE. For many enzymes, not only the biochemical features such as the recognition sequence are given, but also their commercial availability.