CRISPR-Cas9 Mediated DNA Unwinding Detected Using Site-Directed Spin Labeling.

ACS Chem Biol
Authors
Keywords
Abstract

The RNA-guided CRISPR-Cas9 nuclease has revolutionized genome engineering, yet its mechanism for DNA target selection is not fully understood. A crucial step in Cas9 target recognition involves unwinding of the DNA duplex to form a three-stranded R-loop structure. Work reported here demonstrates direct detection of Cas9-mediated DNA unwinding by a combination of site-directed spin labeling and molecular dynamics simulations. The results support a model in which the unwound nontarget strand is stabilized by a positively charged patch located between the two nuclease domains of Cas9 and reveal uneven increases in flexibility along the unwound nontarget strand upon scissions of the DNA backbone. This work establishes the synergistic combination of spin-labeling and molecular dynamics to directly monitor Cas9-mediated DNA conformational changes and yields information on the target DNA in different stages of Cas9 function, thus advancing mechanistic understanding of CRISPR-Cas9 and aiding future technological development.

Year of Publication
2017
Journal
ACS Chem Biol
Volume
12
Issue
6
Pages
1489-1493
Date Published
2017 06 16
ISSN
1554-8937
DOI
10.1021/acschembio.6b01137
PubMed ID
28437608
PubMed Central ID
PMC5501335
Links
Grant list
R01 GM106056 / GM / NIGMS NIH HHS / United States
S10 RR028992 / RR / NCRR NIH HHS / United States
U01 GM103804 / GM / NIGMS NIH HHS / United States