Gutiérrez G, Márquez L, Marín A
Departamento de Genética, Universidad de Sevilla, Spain.
Nucleic Acids Res. 1996 Jul 1;24(13):2525-7. doi: 10.1093/nar/24.13.2525.
The variation in base composition at the three codon sites in relation to gene expressivity, the latter estimated by the Codon Adaptation Index, has been studied in a sample of 1371 Escherichia coli genes. Correlation and regression analyses show that increasing expression levels are accompanied by higher frequencies of base G at first, of base A at second and of base C at third codon positions. However, correlation between expressivity and base compositional biases at each codon site was only significant and positive at first codon position. The preference for G-starting codons as gene expression level increases is discussed in terms of translational optimization.
在1371个大肠杆菌基因样本中，研究了与基因表达能力相关的三个密码子位点的碱基组成变化，基因表达能力由密码子适应指数估算。相关性和回归分析表明，表达水平的提高伴随着密码子第一、第二和第三位上碱基G、A和C出现频率的增加。然而，每个密码子位点的表达能力与碱基组成偏差之间的相关性仅在密码子第一位上显著且呈正相关。从翻译优化的角度讨论了随着基因表达水平提高对以G开头密码子的偏好。
