Sankpal, Umesh T and Rao, Desirazu N (2002) Mutational analysis of conserved residues in HhaI DNA methyltransferase. In: Nucleic-Acids-Research, 30 (12). pp. 2628-2638.
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HhaI DNA methyltransferase belongs to the C5-cytosine methyltransferase family, which is characterized by the presence of a set of highly conserved amino acids and motifs present in an invariant order. HhaI DNA methyltransferase has been subjected to a lot of biochemical and crystallographic studies. A number of issues, especially the role of the conserved amino acids in the methyltransferase activity, have not been addressed. Using sequence comparison and structural data, a structure-guided mutagenesis approach was undertaken, to assess the role of conserved amino acids in catalysis. Site-directed mutagenesis was performed on amino acids involved in cofactor S-adenosyl-L-methionine (AdoMet) binding (Phe18, Trp41, Asp60 and Leu100). Characterization of these mutants, by in vitro /in vivo restriction assays and DNA/AdoMet binding studies, indicated that most of the residues present in the AdoMet-binding pocket were not absolutely essential. This study implies plasticity in the recognition of cofactor by HhaI DNA methyltransferase.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Oxford University Press|
|Department/Centre:||Division of Biological Sciences > Biochemistry|
|Date Deposited:||29 Jan 2008|
|Last Modified:||19 Sep 2010 04:41|
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