کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4497355 1318930 2010 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The level of cytosine is usually much higher than the level of guanine in two-fold degenerated sites from third codon positions of genes from Simplex- and Varicelloviruses with G+C higher than 50%
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم کشاورزی و بیولوژیک (عمومی)
پیش نمایش صفحه اول مقاله
The level of cytosine is usually much higher than the level of guanine in two-fold degenerated sites from third codon positions of genes from Simplex- and Varicelloviruses with G+C higher than 50%
چکیده انگلیسی
We studied usage of cytosine and guanine in 914 genes from completely sequenced genomes of five Simplex- and seven Varicelloviruses. In genes with total GC-content higher than 50% usage of cytosine is usually higher than usage of guanine (an average difference for genes with G+C higher than 70% reaches 4.0%). This difference is caused mostly by the elevated usage of cytosine in two-fold degenerated sites situated in third codon positions relatively to the usage of guanine in two-fold degenerated sites situated in third codon positions (an average difference for genes with G+C higher than 70% is equal to 28.2%). The usage of amino acids that are encoded by codons containing cytosine in two-fold degenerated sites situated in third codon positions (AA2TC) is much higher than the usage of amino acids encoded by codons containing guanine in two-fold degenerated sites situated in third codon positions (AA2AG). The usage of AA2AG declines much more steeply with the growth of GC-content than the usage of AA2TC. This effect is the consequence of the nature of genetic code and of the negative selection. In GC-rich genes the usage of cytosine in four-fold degenerated sites is only a little (but significantly) higher than the usage of guanine (in genes with G+C higher than 70% an average difference is equal to 4.3%). This difference may be caused by transcription-associated mutational pressure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Theoretical Biology - Volume 266, Issue 1, 7 September 2010, Pages 88-98
نویسندگان
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