Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 156.68 kDa 
• Atom Count: 10,404 
• Modelled Residue Count: 1,221 
• Deposited Residue Count: 1,267 
• Unique protein chains: 1
• Unique nucleic acid chains: 1

 6NME

Structure of LbCas12a-crRNA

• PDB DOI: 10.2210/pdb6NME/pdb
• EM Map EMD-0449: EMDB EMDataResource

• Classification: UNKNOWN FUNCTION/RNA
• Organism(s): Lachnospiraceae bacterium ND2006
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2019-01-10 Released: 2019-06-12 
• Deposition Author(s): Chang, L., Li, Z., Zhang, H.

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 5.67 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structural Basis for the Inhibition of CRISPR-Cas12a by Anti-CRISPR Proteins.

Zhang, H., Li, Z., Daczkowski, C.M., Gabel, C., Mesecar, A.D., Chang, L.

(2019) Cell Host Microbe 25: 815

• PubMed: 31155345 
• DOI: 10.1016/j.chom.2019.05.004
• Primary Citation of Related Structures:  
  6NM9, 6NMA, 6NMC, 6NMD, 6NME, 6OMV


• PubMed Abstract: 
  

CRISPR-Cas12a (Cpf1), a type V CRISPR-associated nuclease, provides bacterial immunity against bacteriophages and plasmids but also serves as a tool for genome editing. Foreign nucleic acids are integrated into the CRISPR locus, prompting transcription of CRISPR RNAs (crRNAs) that guide Cas12a cleavage of foreign complementary DNA. However, mobile genetic elements counteract Cas12a with inhibitors, notably type V-A anti-CRISPRs (AcrVAs). We present cryoelectron microscopy structures of Cas12a-crRNA bound to AcrVA1 and AcrVA4 at 3.5 and 3.3 Å resolutions, respectively. AcrVA1 is sandwiched between the recognition (REC) and nuclease (NUC) lobes of Cas12a and inserts into the binding pocket for the protospacer-adjacent motif (PAM), a short DNA sequence guiding Cas12a targeting. AcrVA1 cleaves crRNA in a Cas12a-dependent manner, inactivating Cas12a-crRNA complexes. The AcrVA4 dimer is anchored around the crRNA pseudoknot of Cas12a-crRNA, preventing required conformational changes for crRNA-DNA heteroduplex formation. These results uncover molecular mechanisms for CRISPR-Cas12a inhibition, providing insights into bacteria-phage dynamics.

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Organizational Affiliation: 

Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA. Electronic address: [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cpf1	A	1,227	Lachnospiraceae bacterium ND2006	Mutation(s): 0
UniProt
Find proteins for A0A182DWE3 (Lachnospiraceae bacterium ND2006) Explore A0A182DWE3  Go to UniProtKB:  A0A182DWE3

Entity ID: 2
Molecule	Chains	Length	Organism	Image
crRNA	B [auth G]	40	Lachnospiraceae bacterium ND2006

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
MG	C [auth A], D [auth G]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 5.67 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	RELION	3.0b

Structure Validation

Entry History 

Deposition Data

• Released Date: 2019-06-12 
Deposition Author(s): Chang, L., Li, Z., Zhang, H.

Revision History  

• Version 1.0: 2019-06-12
  Type: Initial release
  
• Version 1.1: 2019-06-26
  Changes: Data collection, Database references
• Version 1.2: 2019-12-18
  Changes: Other