不具有3-碱基周期性的编码序列初探  

Tentative Study of the Coding Sequences Without 3-base Periodicity

作　　者：张静[1] 石秀凡[2] 

机构地区：[1]云南大学应用统计中心,昆明650091 [2]中国科学院昆明动物研究所,昆明650223

出　　处：《生物化学与生物物理进展》2002年第2期267-272,共6页Progress In Biochemistry and Biophysics

基　　金：国家教育部科研重点基金资助项目 ( 0 0 2 46 )~~

摘　　要：对 12 0个较短编码序列 (<12 0 0bp)的Fourier频谱进行分析表明 ,3 碱基周期性在短编码序列中并不是绝对存在的 .统计分析提示 ,编码序列有无 3 碱基周期性与序列的碱基组成和分布、所编码蛋白质氨基酸的选用和顺序以及同义密码子的使用都有一定的关系 .一般地 ,非周期 3序列中A +U含量高于G +C含量 ,周期 3序列的情况则相反 ;非周期 3序列中碱基在密码子三个位点上的分布比周期 3序列中的分布均匀 ;非周期 3序列密码子和氨基酸的使用偏向没有周期 3序列的大 .在利用Fourier分析方法预测DNA序列中的基因和外显子时 。Fourier spectra of 120 short coding sequences (<1 200 bp) show that not all coding sequences are characterized by 3-base periodicity. Statistical analysis suggests that whether a coding sequence has 3-base periodicity may be related to the composition and distribution of bases, the usage and the order of the amino acids of the encoded protein as well as the synonymous codon usage. Generally, the content of A+U is higher than that of G+C in non-period-3 sequences, inversely in period-3 sequences. In the three codon positions, the base distribution in the non-periodic-3 sequences is more uniform than in the periodic-3 sequences. The usage biases of the amino acids and the codons in non-period-3 sequences are weaker than that in period-3 sequences. All of these phenomena should be considered sufficiently in predicting the genes and exons of DNA sequences by Fourier analysis method.

关 键 词：编码序列 FOURIER分析 3-碱基周期性 非3-碱基周期性 

分 类 号：Q755[生物学—分子生物学] Q617