Studies of DNA Methyltransferases

项目描述（申请人提供）：本项目采用太平洋生物科技公司最新开发的SMRT测序技术。除了提供DNA碱基序列外，该方法还允许检测修饰碱基。DNA甲基转移酶传统上很难表征，因此，我们目前还不知道任何DNA甲基转移酶的准确DNA识别特异性。在那些构成限制修改系统一部分的情况下，确实如此

DESCRIPTION (provided by applicant): This project takes advantage of a DNA sequencing technology newly developed by Pacific Biosciences called SMRT sequencing. In addition to providing the DNA base sequence, this approach also allows the detection of modified bases. DNA methyltransferases have traditionally been rather difficult to characterize and as a result, we do not currently know the accurate DNA recognition specificity of any DNA methyltransferases. In the case of those that form part of restriction-modification systems, it has always been assumed that they will have the same recognition specificity as the restriction enzyme. However, in some systems preliminary results indicated that this might not be so, and we now in a position to test that explicitly. A knowledge of the specificity will be key on many fronts. Firstly, in some cases it will allow these methyltransferases to become valuable commercial reagents. Secondly, we expect to discover novel DNA methyltransferases with properties that would make them suitable for specific applications. One such enzyme discovered very recently, is M.EcoGI, which appears to recognize all A residues in a sequence and convert them at very high efficiency to N6- methyladenine. The results of this project will also greatly enhance the value of the cloned restriction-modification systems that we have at New England Biolabs and will also help considerably in the functional annotation of newly determined DNA sequences. It is an ideal blend of academic and commercial research and therefore is especially suited for New England Biolabs.