Pycsar
Description
The pyrimidine cyclase system for antiphage resistance (Pycsar) (N/A) is composed of at least two proteins: a cyclase and diverse effectors. The Pycsar defense system is related to the CBASS but differs in the signaling molecule produced by the cyclase.
In turn, phages encode anti-Pycsar (Apyc) proteins encoded that counteract Pycsar defenses (N/A) .
Molecular mechanisms
Pycsar uses cyclic nucleotide (pyrimidine cyclase, cCMP and cUMP) signals to induce cell death via diverse effectors activation and prevent viral propagation.
While Apyc degrades cyclic nucleotide signals to prevent host immune responses (N/A, N/A) .
Example of genomic structure
The Pycsar is composed of at least 2 proteins: a Cyclase and an Effector.
Like the CBASS system, it can encode for a variety of different effectors.
Here is an example found in the RefSeq database:
The Pycsar system in Nocardioides sambongensis (GCF_006494815.1, NZ_CP041091) is composed of 2 proteins 2TM_5 (WP_141014207.1) AG_cyclase (WP_141014208.1)
Distribution of the system among prokaryotes
Structure
Group | Structure | Foldseek | System | Gene name | Subtype | Proteins in structure | System genes | Prediction type | N genes in sys | pLDDT | iptm+ptm | pDockQ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No data available | ||||||||||||