同义密码子用语与蛋白质二级结构信息

Relations between synonymous codon usage and protein structure

对人体 1 1 7个蛋白质和大肠杆菌的 1 85个蛋白质的各二级结构相对应的mRNA序列中的同义密码子与氨基酸上下文关联熵、蛋白质序列中氨基酸与氨基酸上下文关联熵作了统计分析 ,发现密码子关联确实比氨基酸关联对蛋白质二级结构提供的信息量大 ,而且人蛋白质中同义密码子提供的二级结构信息比大肠杆菌中多 .同时 ,证明了在相对信息剩余大于等于 3 0 %的情况下 ,Adzhubei给出的九种氨基酸中的八种其同义密码子在某些二级结构中明显的携带结构信息 ;此外A ,N ,D ,R ,H ,C ,Y这几种氨基酸的同义密码子在某些二级结构中也明显地携带结构信息 .

The contexts of codons-amino acid in mRNA and of amino acid-amino acid in amino acid sequences which coded secondary structures of 117 Human and 185 Ecoli proteins were statistically analyzed. It was shown that the contexts of codons provided more information for coding the secondary structures of proteins than that of the amino acids. The number of the codons providing the secondary structure information in human proteins was more than that in Ecoil proteins. It was found that the codons considered to carry no evident structure information took the information of the secondary structure when the relative information residue was more than three percent.