Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2018 Jul 17;9:2777. doi: 10.1038/s41467-018-05245-x

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2018

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

PMC Copyright notice

Fig. 6 — Proposed model for DNA target recognition and cleavage by AsCas12a RNP. An AsCas12a RNP first binds dsDNA and then diffuses along it (facilitated target searches including 1D diffusion). When an AsCas12a RNP encounters its target site, PAM-induced local unwinding by AsCas12a mediates DNA–RNA base pairing for checking complementarity (R-loop initiation). If the length of the R-loop is not sufficient (<17 bp), the AsCas12a RNP easily comes off the DNA (low stability under partial R-loop formation). Once a sufficiently long R-loop is formed (≥17 bp), the AsCas12a RNP strongly holds the DNA and is ready for DNA cleavage. After stable R-loop formation, AsCas12a sequentially cleaves the DNA, first the non-target strand and then the target strand, regardless of the presence of a PAM (PAM-independent sequential DNA cleavage). After successful DNA cleavage, AsCas12a quickly releases the PAM-distal DNA fragment but continues to hold the other fragment that contains both the PAM and protospacer