DNA: DNA (5'-D(*TP*GP*AP*TP*GP*GP*CP*AP*GP*AP*GP*TP*AP*CP*TP*AP*G)-3')
RNA: RNA (137-MER)
DNA: DNA (34-MER)
キーワード
CRISPR-Cas / RNA BINDING PROTEIN-RNA-DNA complex
機能・相同性
機能・相同性情報
maintenance of CRISPR repeat elements / 3'-5' exonuclease activity / DNA endonuclease activity / defense response to virus / 加水分解酵素; エステル加水分解酵素 / DNA binding / RNA binding / metal ion binding 類似検索 - 分子機能
Japan Agency for Medical Research and Development (AMED)
JP23ama121012
日本
引用
ジャーナル: Nature / 年: 2024 タイトル: Structural basis for pegRNA-guided reverse transcription by a prime editor. 著者: Yutaro Shuto / Ryoya Nakagawa / Shiyou Zhu / Mizuki Hoki / Satoshi N Omura / Hisato Hirano / Yuzuru Itoh / Feng Zhang / Osamu Nureki / 要旨: The prime editor system composed of Streptococcus pyogenes Cas9 nickase (nSpCas9) and engineered Moloney murine leukaemia virus reverse transcriptase (M-MLV RT) collaborates with a prime editing ...The prime editor system composed of Streptococcus pyogenes Cas9 nickase (nSpCas9) and engineered Moloney murine leukaemia virus reverse transcriptase (M-MLV RT) collaborates with a prime editing guide RNA (pegRNA) to facilitate a wide variety of precise genome edits in living cells. However, owing to a lack of structural information, the molecular mechanism of pegRNA-guided reverse transcription by the prime editor remains poorly understood. Here we present cryo-electron microscopy structures of the SpCas9-M-MLV RTΔRNaseH-pegRNA-target DNA complex in multiple states. The termination structure, along with our functional analysis, reveals that M-MLV RT extends reverse transcription beyond the expected site, resulting in scaffold-derived incorporations that cause undesired edits at the target loci. Furthermore, structural comparisons among the pre-initiation, initiation and elongation states show that M-MLV RT remains in a consistent position relative to SpCas9 during reverse transcription, whereas the pegRNA-synthesized DNA heteroduplex builds up along the surface of SpCas9. On the basis of our structural insights, we rationally engineered pegRNA variants and prime-editor variants in which M-MLV RT is fused within SpCas9. Collectively, our findings provide structural insights into the stepwise mechanism of prime editing, and will pave the way for the development of a versatile prime editing toolbox.