Ishigami M, Nagano K, Tonotsuka N
Biosystems. 1977 Dec;9(4):229-43. doi: 10.1016/0303-2647(77)90007-7.
The origin and development of the protein synthesis mechanism is considered in four successive steps. The genetic code is supposed to be controlled by the relative amount (availability) of various amino acids and nucleotides on the one hand, and utility on each amino acid in the polypeptide. on the other hand. Thus, more simple (inutile) and abundant amino acids tended to correspond to codons which were rich in the less frequent base species, G and C. Features of primitive tRNA in the discrimination of amino acid are discussed. Primitive tRNA is proposed to have a discriminator site for amino acid and, separated from it, an anticodon site for interaction with nucleotides. A hypothetical course of subdivision of various nucleic acid species is proposed. In the scheme, mRNA and ribosomal RNA (rRNA) were derived from more primitive insoluble RNA. DNA appeared in the late, not first, step of the development. Several other aspects of evolutionary development of the whole protein synthesis mechanism, e.g., role of the discriminator site on primitive tRNA, modification and subdivision of code catalogue into a more precise specification of amino acids, and possible primordial interactions between tRNA and tRNA-binding sites on insoluble rRNA, are discussed.
蛋白质合成机制的起源与发展可分为四个连续步骤来探讨。一方面，遗传密码被认为受各种氨基酸和核苷酸的相对量（可利用性）控制，另一方面，受多肽中每种氨基酸的实用性控制。因此，更简单（无用）且丰富的氨基酸往往对应于富含较少出现的碱基种类（G和C）的密码子。文中讨论了原始tRNA在氨基酸识别方面的特征。原始tRNA被认为具有一个氨基酸识别位点，与之分开的是一个用于与核苷酸相互作用的反密码子位点。文中提出了各种核酸种类细分的假设过程。在该方案中，信使核糖核酸（mRNA）和核糖体核糖核酸（rRNA）源自更原始的不溶性核糖核酸。脱氧核糖核酸（DNA）出现在发展过程的后期，而非第一步。文中还讨论了整个蛋白质合成机制进化发展的其他几个方面，例如原始tRNA上识别位点的作用、密码子目录的修饰和细分以更精确地指定氨基酸，以及tRNA与不溶性rRNA上tRNA结合位点之间可能的原始相互作用。
