High resolution structure of a cyanophage deduced which paves the way for more accurate predictions of climate change.
Cyanophages, viruses that infect cyanobacteria, are abundant in the oceans and have a profound influence on cyanobacterial metabolism, evolution, and community dynamics. These viruses play a crucial role in global biogeochemical cycles by impacting host photosynthesis and carbon fixation. Among cyanophages, the T7-like podoviruses, including the recently discovered MPP-C clade, exhibit unique characteristics and infection kinetics. However, the lack of high-resolution structural information has hindered our understanding of their infection mechanisms.
Led by Prof. Dang Shangyu and Prof. Zeng Qinglu, the research teams employed single-particle cryo-electron microscopy to study the virus, unveiling insights into the head assembly and the molecular interaction of the portal-tail complex. By comparing the structure with other viruses and observing changes in components during infection, the researchers acquired valuable information on the evolution and infection processes of similar viruses.
“We believe this high-resolution native structure of cyanophage is an important and timely contribution to the field of bacteriophages for the understanding of viral infection,” said Prof. Dang.
Cyanobacteria are crucial for Earth’s ecosystems as they produce oxygen and serve as a food and fuel source. Infections by cyanophages can alter bacterial behavior, affecting their energy production from sunlight and causing significant carbon loss annually. Understanding the viruses’ mechanisms and their impact on bacteria, oceans, and climate is essential.
“Cyanobacteria are highly abundant in Hong Kong waters and play a major role in global CO2 fixation. The global abundance and carbon fixation capacity of cyanobacteria are important for calculating the marine carbon budget. Cyanophages are a major cause of cyanobacteria death. Studying the infection process of cyanophages is important for understanding how they regulate cyanobacterial populations, which is crucial for the accurate estimation of the global carbon budget and for the prediction of climate change,” Prof. Zeng added.
Moreover, insights into their infection processes can aid in the development of virus-based strategies to control harmful cyanobacteria in freshwater, benefiting agriculture and ensuring clean drinking water. The team’s findings were published in the journal Nature Communications, and future research aims to further explore the virus’s infection process and resolve unresolved parts of its structure relating to host recognition and infection.
Cai, L., Liu, H., Zhang, W. et al.Cryo-EM structure of cyanophage P-SCSP1u offers insights into DNA gating and evolution of T7-like viruses. Nat Commun14, 6438 (2023). https://doi.org/10.1038/s41467-023-42258-7