ego 發問時間: 科學生物學 · 2 0 年前

DNA polymerase如何取代primer?


細胞內DNA複製時,DNA polymerase需先有一段引子才可以延長核苷酸鏈

最後,另一種DNA polymerase會移除primer並以DNA取代之

問題來了,當primer移除了,DNA polymerase又是如何以DNA取代?

不是說 不可以憑空製造DNA了嗎?


1 個解答

  • ?
    Lv 6
    2 0 年前

    DNA polymerase I will only remove primer when the two Okazaki fragments are adjecent to each other. So the replicated strand of DNA from the next Okazaki fragment wll extend and terminate at the RNA primer, and then DNAPI will come in to remove the RNA primer and extend with dNTP. This extension will use the already synthesized replicated DNA that is now next to where the old RNA primer was. So DNAPI still works off a free 3' OH in order to extend, and these replicated DNA act as the "primer".

    I hope you will understand me...

    參考資料: I am a graduate student in genetics.