Bacterial virus anti-defence systems · sequence & structure resource

Encyclopaedia of Bacterial Virus Anti-Defence Systems


Protein: AcrIIA29

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Overview

Mode of Action (MoA) binds to SpyCas9 via the REC3 domain, inhibiting DNA loading.
Evidence AcrIIA29 was identified from a Streptococcus prophage and tested using a plasmid interference assay in E. coli. In this setup, E. coli cells were engineered to express St3Cas9 and an sgRNA targeting a co-transformed antibiotic resistance plasmid. Cas9-mediated cleavage of this plasmid reduced colony formation on selective media. Co-expression of AcrIIA29 partially restored colony formation, indicating moderate anti-CRISPR activity. In vitro cleavage assays revealed that AcrIIA29 inhibited DNA cleavage without affecting Cas9’s DNA binding ability.
MoA Category binds and inhibits host defence system
Subtype(s) of the defence system(s) inhibited by the protein Defence Subtype Streptococcus thermophilus and Streptococcus pyogenes type II-A CRISPR-Cas
Relevant publication(s) DOI 10.1093/nar/gkac099
Other components of the anti-defence system Multicomponent System -
Known structure in PDB PDB ID -
Genome(s) encoding the protein Protein Source MGE in Streptococcus pyogenes NS3335
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: -

MKPSQKIKWLLTATGITTYKIGKDIEESTQFLDRYKNDPEKIGGMRLEKAEKLLEYISNLRQEDVIKTNWNNQQILVQNSTEKEITKYFNSYPFAIKLNWIKPHKEMFIVNFDTTSNKTFRKYPYDLKNLYFLVDKNRDKMSQFAEFLIICGRKSHFGGSRVLYEVEGKKYQIIFSIKRPSELGPTIRLINVVETDTYRDDLVPKISEEESILRSEDLDLKGKRVSIKDSELLELMSIIDN