Skip Navigation

This Article
Right arrow Print PDF (6203K)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (50)
Right arrowRequest Permissions
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Wyszynski, M. W.
Right arrow Articles by Bhagwat, A. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wyszynski, M. W.
Right arrow Articles by Bhagwat, A. S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nucleic Acids Research, 1993, Vol. 21, No. 2 295-301
© 1993

ENZYMOLOGY

The cysteine conserved among DNA cytosine methylasesis required for methyl transfer, but not for specific DNA binding

Michael W. Wyszynski, Sam Gabbara, E. A. Kubareva1, E. A. Romanova1, T. S. Oretskaya1, E. S. Gromova1, Z. A. Shabarova1 and Ashok S. Bhagwat*

Department of Chemistry, Wayne State University Detroit, Ml 48202, USA 1Department of Chemistry, Moscow State University Moscow 119899, Russia

*To whom correspondence should be addressed

Received September 13, 1992. Revised November 17, 1992. Accepted November 17, 1992.

All DNA (cytoslne-5)-methyrtransferases contain a single conserved cysteine. It has been proposed that this cysteine Initiates catalysis by attacking the C6 of cytosine and thereby activating the normally inert C5 position. We show here that substitutions of this cysteine In the E.coli methylase M.EcoRII with either serlne or tryptophan results in a complete loss of ability to transfer methyl groups to DNA. Interestingly, mutants with either serine or glycine substitution bind tightly to substrate DNA. These mutants resemble the wild-type enzyme In that their binding to substrate is not eliminated by the presence of non-specific DNA In the reaction, It Is sensitive to methylatlon status of the substrate and Is stimulated by an analog of the methyl donor. Hence the conserved cysteine Is not essential for the specific stable binding of the enzyme to its substrate. However, substitution of the cysteine with the bulkier tryptophan does reduce DNA binding. We also report here a novel procedure for the synthesis of DNA containing 5-fluorocytosine. Further, we show that a DNA substrate for M.EcoRII in which the target cytosine is replaced by 5-fluorocytosine Is a mechanism-based Inhibitor of the enzyme and that it forms an irreversible complex with the enzyme. As expected, this modified substrate does not form irreversible complexes with the mutants.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Mol. Cell. Biol.Home page
S.-i. Takebayashi, T. Tamura, C. Matsuoka, and M. Okano
Major and Essential Role for the DNA Methylation Mark in Mouse Embryogenesis and Stable Association of DNMT1 with Newly Replicated Regions
Mol. Cell. Biol., December 1, 2007; 27(23): 8243 - 8258.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Cell. Biol.Home page
M. Damelin and T. H. Bestor
Biological Functions of DNA Methyltransferase 1 Require Its Methyltransferase Activity
Mol. Cell. Biol., June 1, 2007; 27(11): 3891 - 3899.
[Abstract] [Full Text] [PDF]

Home page
 Mol Cancer ResHome page
D. J. Weisenberger, M. Velicescu, J. C. Cheng, F. A. Gonzales, G. Liang, and P. A. Jones
Role of the DNA Methyltransferase Variant DNMT3b3 in DNA Methylation
Mol. Cancer Res., January 1, 2004; 2(1): 62 - 72.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
Y. V. R. Reddy and D. N. Rao
Probing the Role of Cysteine Residues in the EcoP15I DNA Methyltransferase
J. Biol. Chem., September 11, 1998; 273(37): 23866 - 23876.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
X. Xu and S. P. Burke
Roles of Active Site Residues and the NH(2)-terminal Domain in the Catalysis and Substrate Binding of Human Cdc25
J. Biol. Chem., March 1, 1996; 271(9): 5118 - 5124.
[Abstract] [Full Text] [PDF]

Home page
 DevelopmentHome page
H Lei, S. Oh, M Okano, R Juttermann, K. Goss, R Jaenisch, and E Li
De novo DNA cytosine methyltransferase activities in mouse embryonic stem cells
Development, January 10, 1996; 122(10): 3195 - 3205.
[Abstract] [PDF]

Home page
 J. Biol. Chem.Home page
F. D. Araujo, S. Croteau, A. D. Slack, S. Milutinovic, P. Bigey, G. B. Price, M. Zannis-Hajopoulos, and M. Szyf
The DNMT1 Target Recognition Domain Resides in the N Terminus
J. Biol. Chem., March 2, 2001; 276(10): 6930 - 6936.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.