کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10755089 1050367 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Time-resolved fluorescence of 2-aminopurine in DNA duplexes in the presence of the EcoP15I Type III restriction-modification enzyme
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Time-resolved fluorescence of 2-aminopurine in DNA duplexes in the presence of the EcoP15I Type III restriction-modification enzyme
چکیده انگلیسی
EcoP15I is a Type III DNA restriction and modification enzyme of Escherichia coli. We show that it contains two modification (Mod) subunits for sequence-specific methylation of DNA and one copy of a restriction endonuclease (Res) subunit for cleavage of DNA containing unmethylated target sequences. Previously the Mod2 dimer in the presence of cofactors was shown to use nucleotide flipping to gain access to the adenine base targeted for methylation (Reddy and Rao, J. Mol. Biol. 298 (2000) 597-610.). Surprisingly the Mod2 enzyme also appeared to flip a second adenine in the target sequence, one which was not subject to methylation. We show using fluorescence lifetime measurements of the adenine analogue, 2-aminopurine, that only the methylatable adenine undergoes flipping by the complete Res1Mod2 enzyme and that this occurs even in the absence of cofactors. We suggest that this is due to activation of the Mod2 core by the Res subunit.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 449, Issue 1, 20 June 2014, Pages 120-125
نویسندگان
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