7M9A

ADP-AlF3 bound TnsC structure from ShCAST system

Summary for 7M9A

• Entry DOI: 10.2210/pdb7m9a/pdb
• EMDB information: 23720 23721 23722 23723 23724 23725 23726
• Descriptor: TnsC, DNA (27-MER), ADENOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: crispr, transposition, aaa+ atpase, tn7, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Scytonema hofmannii; More
• Total number of polymer chains: 14
• Total formula weight: 398187.29

Authors

Park, J.,Tsai, A.W.L.,Mehrotra, E.,Kellogg, E.H. (deposition date: 2021-03-30, release date: 2021-07-28, Last modification date: 2024-05-29)

Primary citation

Park, J.U.,Tsai, A.W.,Mehrotra, E.,Petassi, M.T.,Hsieh, S.C.,Ke, A.,Peters, J.E.,Kellogg, E.H.
Structural basis for target site selection in RNA-guided DNA transposition systems.
Science, 373:768-774, 2021

PubMed Abstract: 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 These mechanistic findings provide the underpinnings for engineering CRISPR-associated transposition systems for research and therapeutic applications.

PubMed: 34385391
DOI: 10.1126/science.abi8976

Experimental method

ELECTRON MICROSCOPY (3.9 Å)