|PROSITE documentation PDOC00089|
C-5 cytosine-specific DNA methylases (EC 18.104.22.168) (C5 Mtase) are enzymes that specifically methylate the C-5 carbon of cytosines in DNA [1,2,3]. Such enzymes are found in the proteins described below.
C-5 Mtases share a number of short conserved regions. We selected two of them. The first is centered around a conserved Pro-Cys dipeptide in which the cysteine has been shown  to be involved in the catalytic mechanism; it appears to form a covalent intermediate with the C6 position of cytosine. The second region is located at the C-terminal extremity in type-II enzymes.Note:
In the first position of the second pattern, most known Mtases have Arg or Lys.Expert(s) to contact by email:
December 2004 / Pattern and text revised.
PROSITE methods (with tools and information) covered by this documentation:
|1||Authors||Posfai J., Bhagwat A.S., Roberts R.J.|
|Title||Sequence motifs specific for cytosine methyltransferases.|
|2||Authors||Kumar S., Cheng X., Klimasauskas S., Mi S., Posfai J., Roberts R.J., Wilson G.G.|
|Title||The DNA (cytosine-5) methyltransferases.|
|Source||Nucleic Acids Res. 22:1-10(1994).|
|3||Authors||Lauster R., Trautner T.A., Noyer-Weidner M.|
|Title||Cytosine-specific type II DNA methyltransferases. A conserved enzyme core with variable target-recognizing domains.|
|Source||J. Mol. Biol. 206:305-312(1989).|
|4||Authors||Chen L., MacMillan A.M., Chang W., Ezaz-Nikpay K., Lane W.S., Verdine G.L.|
|Title||Direct identification of the active-site nucleophile in a DNA (cytosine-5)-methyltransferase.|