The Salk Institute, La Jolla, California.
Elife. 2017 Sep 26;6:e31153. doi: 10.7554/eLife.31153.
A highly evolved RNA polymerase ribozyme was found to also be capable of functioning as a reverse transcriptase, an activity that has never been demonstrated before for RNA. This activity is thought to have been crucial for the transition from RNA to DNA genomes during the early history of life on Earth, when it similarly could have arisen as a secondary function of an RNA-dependent RNA polymerase. The reverse transcriptase ribozyme can incorporate all four dNTPs and can generate products containing up to 32 deoxynucleotides. It is likely that this activity could be improved through evolution, ultimately enabling the synthesis of complete DNA genomes. DNA is much more stable compared to RNA and thus provides a larger and more secure repository for genetic information.
一种高度进化的 RNA 聚合酶核酶也被发现能够充当逆转录酶，这种活性以前从未在 RNA 中表现出来过。这种活性被认为在地球生命早期的 RNA 向 DNA 基因组的转变过程中至关重要，当时它可能同样是作为 RNA 依赖性 RNA 聚合酶的次要功能而出现的。逆转录酶核酶可以掺入所有四个 dNTP，并可以生成含有多达 32 个脱氧核苷酸的产物。这种活性很可能通过进化得到改善，最终能够合成完整的 DNA 基因组。与 RNA 相比，DNA 更加稳定，因此为遗传信息提供了更大、更安全的存储库。
