کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5372374 1388875 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photochemical probing of the B-A conformational transition in a linearized pUC19 DNA and its polylinker region
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Photochemical probing of the B-A conformational transition in a linearized pUC19 DNA and its polylinker region
چکیده انگلیسی
We induced the B-to-A conformational transition by ethanol in a linearized pUC19 DNA. A primer extension method was used in combination with UV light irradiation to follow the transition, based on pausing of DNA synthesis due to the presence of damaged bases in the template. Primer extension data highly correlated with the results of another method monitoring the B-A transition, i.e. inhibition of restriction endonuclease cleavage of UV light-irradiated DNA. Primer extension enabled us to locate damaged nucleotides within the region of interest. Most damaged nucleotides were located in B-form trimers, exclusively containing both pyrimidine bases (TTC, TCT, CTC, and CTT), and in a cytosine tetramer. The amount of damaged bases decreased in the course of B-A transition. Some of the damage even disappeared in the A-form, which mainly concerns the C4 and C3 blocks. The cleavage was nearly restored in the A-form within this region (Eco88I). On the contrary the decrease of damage was less significant with thymine dimers, only dropping to 50-60% of the B-form level. Consequently, the cleavage with EcoRI and HindIII remained mostly as before the transition (75% and 60% of uncleaved DNA preserved). We found significant differences in the B- and A-form pattern of UV light-damaged bases within the same region (polylinker) of DNA embedded within long (plasmid) or short (127 bp fragment) DNA molecules. The B-A transition of the fragment was found less cooperative than with linearized plasmid, which was confirmed by both CD spectroscopy and restriction cleavage inhibition.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biophysical Chemistry - Volume 125, Issue 1, January 2007, Pages 237-246
نویسندگان
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