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Title: Structural basis for target site selection in RNA-guided DNA transposition systems
CRISPR-associated transposition systems allow guide RNA–directed integration of a single DNA cargo in one orientation at a fixed distance from a programmable target sequence. We used cryo–electron microscopy (cryo-EM) to define the mechanism that underlies this process by characterizing the transposition regulator, TnsC, from a type V-K CRISPR-transposase system. In this scenario, polymerization of adenosine triphosphate–bound TnsC helical filaments could explain how polarity information is passed to the transposase. TniQ caps the TnsC filament, representing a universal mechanism for target information transfer in Tn7/Tn7-like elements. Transposase-driven disassembly establishes delivery of the element only to unused protospacers. Finally, TnsC transitions to define the fixed point of insertion, as revealed by structures with the transition state mimic ADP•AlF 3 . These mechanistic findings provide the underpinnings for engineering CRISPR-associated transposition systems for research and therapeutic applications.  more » « less
Award ID(s):
1719875
PAR ID:
10325652
Author(s) / Creator(s):
; ; ; ; ; ; ;
Date Published:
Journal Name:
Science
Volume:
373
Issue:
6556
ISSN:
0036-8075
Page Range / eLocation ID:
768 to 774
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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