3维,2维和1维DNA行走的比较研究

对３维，２维和１维ＤＮＡ行走进行了比较研究，对于３维和２维行走，编码序列分维Ｄ，在１．１和１．４之间．１维嘌呤嘧啶行走略高于此值，１维强弱键行走则略低．分维明显偏离２表明碱基关联的存在．这是不同于最近国外由１维行走获得的无关联的结论的．利用定义于２０个碱基范围的分维Ｄａ，证明了编码区的Ｄａ大于非编码区，表明了后者有调节信号引起的碱基偏置．

The Comparative Study of DNA Walk in 3-,2- and 1-Dimensional Base Space

The comparative investigation of DNA walk in 2- d,3- d and 1- d base space is given. The fractal analysis shows that the dimension Df of coding sequences takes value between 1. 1 to 1. 4 for 2-dim. and 3-dim. walk and 1. 2 to 1. 5for 1-dim. walk (purine-pyrimidine rule). Moreover,Df of 1-dim. S-W rule (hydrogen bond rule) is smaller than that deduced from purine-pyrimidine rule. The deviation of these dimensions from 2 shows the existence of base correlation. The fractal dimension D.(defined in a range of 20 bases) of coding sequences is found to be larger than Dn of corresponding introns, 5'-caps and 3'-tails. It implies possibly some regulation signals (biased in base composition) with length smaller than 20bases occurred in these noncoding regions. The above fractal analyses are consistent with our earlier information-theoretic studies.