Taylor F J, Coates D
Department of Botany, University of British Columbia, Vancouver, Canada.
Biosystems. 1989;22(3):177-87. doi: 10.1016/0303-2647(89)90059-2.
For the first time it is shown that each of the three codon bases has a general correlation with a different, predictable amino acid property, depending on position within the codon. In addition to the previously recognized link between the mid-base and the hydrophobic-hydrophilic spectrum, we show that, with the exception of G, the first base is generally invariant within a synthetic pathway. G--coded amino acids show a different order, being found only at the head of the synthetic pathways. The redundancy of the nature of the third base has a previously unrecognised relationship with molecular weight. The bases U and A (transversions) are associated with the most sharply defined or opposite states in both the first and second position, C somewhat less so or intermediate, anf G neutral. The apparently systematic nature of these relationships has profound implications for the origin of the genetic code. It appears to be the remains of the first language of the cell, predating the tRNA/ribosome system, persisting with remarkably little change at a deeper level of organisation than the codon language.
首次表明，三个密码子碱基中的每一个都与一种不同的、可预测的氨基酸特性具有普遍相关性，这取决于其在密码子中的位置。除了之前认识到的中间碱基与疏水-亲水平谱之间的联系外，我们还表明，除了G之外，第一个碱基在合成途径中通常是不变的。由G编码的氨基酸呈现出不同的顺序，仅出现在合成途径的起始位置。第三个碱基性质的冗余与分子量有着此前未被认识到的关系。碱基U和A（颠换）在第一和第二位置与定义最明确或相反的状态相关，C的相关性稍弱或处于中间状态，而G是中性的。这些关系明显的系统性本质对遗传密码的起源有着深远的影响。它似乎是细胞第一种语言的遗留，早于tRNA/核糖体系统，在比密码子语言更深层次的组织水平上以极少的变化留存下来。
