Kuhn C
Gruppe Biophysik, Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule Hönggerberg, CH-8093 Zürich, Switzerland.
Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8620-5. doi: 10.1073/pnas.141379398.
This computer simulation is based on a model of the origin of life proposed by H. Kuhn and J. Waser, where the evolution of short molecular strands is assumed to take place in a distinct spatiotemporal structured environment. In their model, the prebiotic situation is strongly simplified to grasp essential features of the evolution of the genetic apparatus without attempts to trace the historic path. With the tool of computer implementation confining to principle aspects and focused on critical features of the model, a deeper understanding of the model's premises is achieved. Each generation consists of three steps: (i) construction of devices (entities exposed to selection) presently available; (ii) selection; and (iii) multiplication of the isolated strands (R oligomers) by complementary copying with occasional variation by copying mismatch. In the beginning, the devices are single strands with random sequences; later, increasingly complex aggregates of strands form devices such as a hairpin-assembler device which develop in favorable cases. A monomers interlink by binding to the hairpin-assembler device, and a translation machinery, called the hairpin-assembler-enzyme device, emerges, which translates the sequence of R(1) and R(2) monomers in the assembler strand to the sequence of A(1) and A(2) monomers in the A oligomer, working as an enzyme.
这个计算机模拟基于H. 库恩和J. 瓦泽提出的生命起源模型,其中假设短分子链的进化发生在一个独特的时空结构环境中。在他们的模型中,前生物状况被极大地简化,以把握遗传机制进化的基本特征,而不试图追溯其历史路径。借助计算机实现这一工具,局限于原理方面并聚焦于模型的关键特征,从而对模型的前提有了更深入的理解。每一代包括三个步骤:(i)构建当前可用的装置(接受选择的实体);(ii)选择;以及(iii)通过互补复制使分离的链(R寡聚物)倍增,复制过程中偶尔会因复制错配而产生变异。起初,装置是具有随机序列的单链;后来,越来越复杂的链聚集体形成诸如发夹组装装置之类的装置,在有利情况下会不断发展。单体通过与发夹组装装置结合而相互连接,一种称为发夹组装酶装置的翻译机制出现了,它将组装链中R(1)和R(2)单体的序列翻译成A寡聚物中A(1)和A(2)单体的序列,起到酶的作用。