Related Experiment Video
Updated: Jun 3, 2025
09:01
Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi
Published on: September 28, 2022
1.9K
Cad1 turns ATP into phage poison
Jinzhong Lin1, Yuvaraj Bhoobalan-Chitty2, Xu Peng1
1Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Copenhagen, Denmark.
Cell Host & Microbe
|January 9, 2025
Summary
A novel CRISPR-Cas effector, Cad1, was discovered. This enzyme halts phage propagation by converting ATP to ITP, causing host cell growth arrest.
Area of Science:
- Molecular Biology
- Microbial Genetics
- Bacteriophage Research
Background:
- Type III CRISPR-Cas systems provide robust anti-phage immunity.
- CRISPR-Cas effectors include nucleases and membrane-destabilizing proteins.
- The full repertoire of anti-phage mechanisms is not completely understood.
Purpose of the Study:
- To identify and characterize novel effectors involved in the Type III CRISPR-Cas anti-phage response.
- To elucidate the mechanism of action of the newly identified effector Cad1.
- To understand how Cad1 contributes to inhibiting phage propagation.
Main Methods:
- Biochemical assays to study Cad1 enzymatic activity.
- Analysis of ITP accumulation in bacterial hosts.
- Bacterial growth assays under phage infection.
- Genetic manipulation of CRISPR-Cas system components.
Main Results:
- Identification of Cad1 as an accessory effector in Type III CRISPR-Cas systems.
- Demonstration that Cad1 deaminates ATP to inosine triphosphate (ITP).
- Observation of ITP accumulation leading to host growth arrest.
- Confirmation that Cad1 activity inhibits phage propagation.
Conclusions:
- Cad1 represents a new class of CRISPR-Cas effector.
- ITP accumulation is a mechanism for anti-phage defense.
- The discovery of Cad1 expands our understanding of CRISPR-Cas immunity.
Related Concept Videos
01:30Lytic Cycle of Bacteriophages
70.3K
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
70.3K
00:43Lysogenic Cycle of Bacteriophages
61.8K
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
61.8K
02:53CRISPR and crRNAs
16.6K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
16.6K