Biological Assembly 1  

 3D View: Structure

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

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 163.93 kDa 
• Atom Count: 10158 
• Residue Count: 1235 
• Unique protein chains: 1
• Unique nucleic acid chains: 1

6IV6

Cryo-EM structure of AcrVA5-acetylated MbCas12a in complex with crRNA

• DOI: 10.2210/pdb6IV6/pdb
• EMDataResource: EMD-9742

• Classification: IMMUNE SYSTEM/RNA
• Organism(s): Moraxella bovoculi, synthetic construct
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2018-12-02 Released: 2019-04-10 
• Deposition Author(s): Dong, L., Li, N., Guan, X., Zhu, Y., Gao, N., Huang, Z.
• Funding Organization(s): National Natural Science Foundation of China

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

An anti-CRISPR protein disables type V Cas12a by acetylation.

Dong, L., Guan, X., Li, N., Zhang, F., Zhu, Y., Ren, K., Yu, L., Zhou, F., Han, Z., Gao, N., Huang, Z.

(2019) Nat Struct Mol Biol 26: 308-314

• PubMed: 30936526 
• DOI: 10.1038/s41594-019-0206-1
• Primary Citation of Related Structures:  
  6IV6, 6IUF


• PubMed Abstract: 
  

Phages use anti-CRISPR proteins to deactivate the CRISPR-Cas system. The mechanisms for the inhibition of type I and type II systems by anti-CRISPRs have been elucidated. However, it has remained unknown how the type V CRISPR-Cas12a (Cpf1) system is inhibited by anti-CRISPRs. Here we identify the anti-CRISPR protein AcrVA5 and report the mechanisms by which it inhibits CRISPR-Cas12a. Our structural and biochemical data show that AcrVA5 functions as an acetyltransferase to modify Moraxella bovoculi (Mb) Cas12a at Lys635, a residue that is required for recognition of the protospacer-adjacent motif. The AcrVA5-mediated modification of MbCas12a results in complete loss of double-stranded DNA (dsDNA)-cleavage activity. In contrast, the Lys635Arg mutation renders MbCas12a completely insensitive to inhibition by AcrVA5. A cryo-EM structure of the AcrVA5-acetylated MbCas12a reveals that Lys635 acetylation provides sufficient steric hindrance to prevent dsDNA substrates from binding to the Cas protein. Our study reveals an unprecedented mechanism of CRISPR-Cas inhibition and suggests an evolutionary arms race between phages and bacteria.

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Organizational Affiliation: 

HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, China. [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
nuclease	A	1261	Moraxella bovoculi	Mutation(s): 0  Gene Names: AAX07_00205
Find proteins for A0A0U2B2X7 (Moraxella bovoculi) Explore A0A0U2B2X7  Go to UniProtKB:  A0A0U2B2X7

Entity ID: 2
Molecule	Chains	Length	Organism	Image
RNA (59-MER)	G	59	synthetic construct

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
ALY	A	L-PEPTIDE LINKING	C8 H16 N2 O3		LYS

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2018-12-02 
• Released Date: 2019-04-10 
Deposition Author(s): Dong, L., Li, N., Guan, X., Zhu, Y., Gao, N., Huang, Z.

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Funding Organization	Location	Grant Number
National Natural Science Foundation of China	China	31825008
National Natural Science Foundation of China	China	31422014

Revision History 

• Version 1.0: 2019-04-10
  Type: Initial release
  
• Version 1.1: 2019-04-17
  Changes: Data collection, Database references
• Version 1.2: 2019-11-06
  Changes: Data collection, Other