PROSITE documentation PDOC00089C-5 cytosine-specific DNA methylases signatures
C-5 cytosine-specific DNA methylases (EC 2.1.1.37) (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.
- As a component of type II restriction-modification systems in prokaryotes and some bacteriophages. Such enzymes recognize a specific DNA sequence where they methylate a cytosine. In doing so, they protect DNA from cleavage by type II restriction enzymes that recognize the same sequence. The sequences of a large number of type II C-5 Mtases are known.
- In vertebrates, there are a number of C-5 Mtases that methylate CpG dinucleotides. The sequence of the mammalian enzyme is known.
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 [4] 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:Roberts R.J.
Bickle T.
Mugasimangalam R.
December 2004 / Pattern and text revised.
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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. | |
| Source | Gene 74:261-265(1988). | |
| PubMed ID | 3248729 |
| 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). | |
| PubMed ID | 8127644 |
| 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). | |
| PubMed ID | 2716049 |
| 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. | |
| Source | Biochemistry 30:11018-11025(1991). | |
| PubMed ID | 1932026 |
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