Hopfield J J
Proc Natl Acad Sci U S A. 1980 Sep;77(9):5248-52. doi: 10.1073/pnas.77.9.5248.
A mechanism for proofreading biosynthetic processes requiring high accuracy is described. The previously understood "kinetic proofreading" mechanism of enhancing accuracy has distinguishing characteristics such as the non-stoichiometric use of substrate or cosubstrate that have allowed its identification in aspects of DNA and protein synthesis. The proofreading scheme developed here, though generically related, lacks all the previous identifying features. A DNA polymerase proofreading in this manner need neither generate dNMP nor have a 3' leads to 5' exonuclease activity. Protein synthesis could be proofread even with stoichiometric GTP consumption or without elongation factor Tu . GTP. The kinetic scheme that generates this proofreading makes use of an "energy relay" from previous substrate molecules and is a representative of a class of nonequilibrium processes displaying dynamic cooperativity. This proofreading mechanism has its own identifying characteristics, which are sufficiently subtle that they would have generally escaped notice or defied interpretation.
本文描述了一种用于对需要高精度的生物合成过程进行校对的机制。先前理解的提高准确性的“动力学校对”机制具有一些独特特征,例如底物或共底物的非化学计量使用,这使得它能够在DNA和蛋白质合成的各个方面被识别出来。这里开发的校对方案虽然在一般意义上相关,但缺乏所有先前的识别特征。以这种方式进行校对的DNA聚合酶既不需要生成dNMP,也不需要具有3'至5'核酸外切酶活性。即使在化学计量消耗GTP或没有延伸因子Tu·GTP的情况下,蛋白质合成也可以进行校对。产生这种校对的动力学方案利用了来自先前底物分子的“能量中继”,并且是一类显示动态协同性的非平衡过程的代表。这种校对机制有其自身的识别特征,这些特征足够微妙,以至于通常会被忽视或难以解释。