Back to Search
Start Over
Structural basis for anti-CRISPR repression mediated by bacterial operon proteins Aca1 and Aca2.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2021 Dec; Vol. 297 (6), pp. 101357. Date of Electronic Publication: 2021 Oct 28. - Publication Year :
- 2021
-
Abstract
- It has been shown that phages have evolved anti-CRISPR (Acr) proteins to inhibit host CRISPR-Cas systems. Most acr genes are located upstream of anti-CRISPR-associated (aca) genes, which is instrumental for identifying these acr genes. Thus far, eight Aca families (Aca1-Aca8) have been identified, all proteins of which share low sequence homology and bind to different target DNA sequences. Recently, Aca1 and Aca2 proteins were discovered to function as repressors by binding to acr-aca promoters, thus implying a potential anti-anti-CRISPR mechanism. However, the structural basis for the repression roles of Aca proteins is still unknown. Here, we elucidated apo-structures of Aca1 and Aca2 proteins and their complex structures with their cognate operator DNA in two model systems, the Pseudomonas phage JBD30 and the Pectobacterium carotovorum template phage ZF40. In combination with biochemical and cellular assays, our study unveils dimerization and DNA-recognition mechanisms of Aca1 and Aca2 family proteins, thus revealing the molecular basis for Aca1-and Aca2-mediated anti-CRISPR repression. Our results also shed light on understanding the repression roles of other Aca family proteins and autoregulation roles of acr-aca operons.<br />Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article.<br /> (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Subjects :
- Bacteriophages chemistry
Bacteriophages genetics
Models, Molecular
Pectobacterium carotovorum genetics
Pectobacterium carotovorum metabolism
Protein Conformation
Protein Multimerization
Pseudomonas Phages chemistry
Pseudomonas Phages genetics
Pseudomonas Phages metabolism
Pseudomonas aeruginosa genetics
Pseudomonas aeruginosa metabolism
Viral Proteins chemistry
Viral Proteins genetics
Bacteriophages metabolism
Clustered Regularly Interspaced Short Palindromic Repeats
Operon
Pectobacterium carotovorum virology
Pseudomonas aeruginosa virology
Viral Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1083-351X
- Volume :
- 297
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 34756887
- Full Text :
- https://doi.org/10.1016/j.jbc.2021.101357