23VU | pdb_000023vu

Cryo-EM structure of the UnCas12m4a-crRNA-tgDNA ternary complex in the TS-cleaving state

• PDB DOI: https://doi.org/10.2210/pdb23VU/pdb
• EM Map EMD-69297: EMDB EMDataResource

• Classification: DNA BINDING PROTEIN
• Organism(s): bacterium
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2026-02-21 Released: 2026-09-02 
• Deposition Author(s): Morinaga, H., Omura, S.N., Nureki, O.
• Funding Organization(s): Japan Agency for Medical Research and Development (AMED)

---

Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.69 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Intact RuvC catalytic site and bipartite ssDNA kinking are required for Cas12m nuclease activation

Morinaga, H., Omura, S.N., Alfonse, L., Ornstein, A., Kobayashi, T.A., Onishi, K., Makarova, K.S., Shmakov, S.A., Munoz, G., Garrity, A.J., DiTommaso, T., Koonin, E.V., Maben, Z., Nureki, O.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by (software)

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 113.26 kDa 
• Atom Count: 7,035 
• Modeled Residue Count: 699 
• Deposited Residue Count: 748 
• Unique protein chains: 1
• Unique nucleic acid chains: 3

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
UnCas12m4a	A	614	bacterium	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Length	Organism	Image
RNA (56-MER)	B	56	bacterium

Entity ID: 3
Molecule	Chains	Length	Organism	Image
DNA (39-MER)	C	39	bacterium

Entity ID: 4
Molecule	Chains	Length	Organism	Image
DNA (39-MER)	D	39	bacterium

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	G [auth A]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N
MG (Subject of Investigation/LOI)	E [auth A], F [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.69 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-09-02 
Deposition Author(s): Morinaga, H., Omura, S.N., Nureki, O.

---

Funding Organization	Location	Grant Number
Japan Agency for Medical Research and Development (AMED)	Japan	--

Revision History  

• Version 1.0: 2026-09-02
  Type: Initial release