Bacterial virus anti-defence systems · sequence & structure resource

Encyclopaedia of Bacterial Virus Anti-Defence Systems


Protein: AcrIIC6

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Overview

Mode of Action (MoA) binds to sgRNA loaded Cas9 preventing the complex from binding target DNA
Evidence AcrIIC6Nme was identified using a guilt-by-association bioinformatic approach and tested for anti-CRISPR activity via in vivo phage targeting assays. Expression of AcrIIC6Nme in E. coli co-expressing Nme1Cas9 and an sgRNA targeting phage Mu restored phage infectivity, indicating inhibition of CRISPR interference. This inhibition was selective, effective only against closely related type II-C Cas9s (Nme1Cas9, Nme2Cas9, HpaCas9, BoeCas9), but not distantly related variants (GeoCas9, CjeCas9, CdiCas9). In vivo pulldown (ECO_0006249) assays demonstrated that AcrIIC6Nme selectively co-purifies with the Nme1Cas9:sgRNA complex but not apo-Cas9, indicating specific binding to the Cas9:sgRNA binary complex. These results support the activity of AcrIIC6Nme as a selective type II-C anti-CRISPR that binds the loaded Cas9 complex and inhibits DNA targeting.
MoA Category binds and inhibits host defence system
Subtype(s) of the defence system(s) inhibited by the protein Defence Subtype Neisseria meningitidis type II-C CRISPR-Cas
Relevant publication(s) DOI No DOI, master thesis (Khan, A.N., 2021. Characterizing a Novel Type II-C Anti-CRISPR, AcrIIC6)
Other components of the anti-defence system Multicomponent System -
Known structure in PDB PDB ID -
Genome(s) encoding the protein Protein Source Prophages in Neisseria meningitidis and Pasteurella multocida
Defence system(s) inhibited by the protein Defences CRISPR-Cas

3D structure

AlphaFold 3 model.

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Feature viewer - predicted secondary structure

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Pfam annotations

No Pfam domains found

Sequence Viewer

Amino acid position: -

MEIIKTGSYRLEKLSGNTYKVYRHQYAIGTLTEYGEVELTDEIIKGYEKKPHSGYWVSEIEKIIKNR