Cas12a 在力拉伸 DNA 上的目标搜索和切割。

Department of Infectious Disease, Section of Virology, Faculty of Medicine, Imperial College London, London W12 0NN, UK.

Single Molecule Imaging Group, MRC London Institute of Medical Sciences, London W12 0NN, UK.

Phys Chem Chem Phys. 2021 Dec 8;23(47):26640-26644. doi: 10.1039/d1cp03408a.

Using optical tweezers, we investigate target search and cleavage by CRISPR-Cas12a on force-stretched λ-DNA. Cas12a uses fast, one-dimensional hopping to locate its target. Binding and cleavage occur rapidly and specifically at low forces (≤5 pN), with a 1.8 nm rate-limiting conformational change. Mechanical distortion slows diffusion, increases off-target binding but hinders cleavage.

我们使用光镊研究了 CRISPR-Cas12a 在力拉伸 λ-DNA 上的目标搜索和切割。Cas12a 利用快速的一维跳跃来定位其目标。在低力（≤5 pN）下，Cas12a 快速且特异性地结合并切割，其速率限制构象变化为 1.8nm。机械变形会降低扩散速度，增加非靶标结合，但会阻碍切割。