Nucleus-forming phages (chimalliviruses) encode numerous genes responsible for creating intricate structures for viral replication. Research on this newly appreciated family of phages has begun to reveal the mechanisms underlying the subcellular organization of the nucleus-based phage replication cycle. These discoveries include the structure of the phage nuclear shell, the identification of a membrane-bound early phage infection intermediate, the dynamic localization of phage RNA polymerases, the phylogeny and core genome of chimalliviruses, and the variation in replication mechanisms across diverse nucleus-forming phages. This research is being propelled forward through the application of fluorescence microscopy and cryo-electron microscopy and the innovative use of new tools such as proximity labeling and RNA-targeting Clustered Regularly Interspaced Short Palindromic Repeats-Cas systems.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.mib.2024.102457 | DOI Listing |
Sci Rep
January 2025
School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA.
As nucleus-forming phages become better characterized, understanding their unifying similarities and unique differences will help us understand how they occupy varied niches and infect diverse hosts. All identified nucleus-forming phages fall within the Chimalliviridae family and share a core genome of 68 unique genes including chimallin, the major nuclear shell protein. A well-studied but non-essential protein encoded by many nucleus-forming phages is PhuZ, a tubulin homolog which aids in capsid migration, nucleus rotation, and nucleus positioning.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
The Chimalliviridae family of bacteriophages (phages) form a proteinaceous nucleus-like structure during infection of their bacterial hosts. This phage 'nucleus' compartmentalises phage DNA replication and transcription, and shields the phage genome from DNA-targeting defence systems such as CRISPR-Cas and restriction-modification. Their insensitivity to DNA-targeting defences makes nucleus-forming jumbo phages attractive for phage therapy.
View Article and Find Full Text PDFAntibacterial proteins inhibiting have been identified in various phages and explored as antibiotic alternatives. Here, we isolated a phiKZ-like phage, Churi, which encodes 364 open reading frames. We examined 15 early-expressed phage proteins for their ability to inhibit bacterial growth, and found that gp335, closely related to phiKZ-gp14, exhibits antibacterial activity.
View Article and Find Full Text PDFbioRxiv
May 2024
School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
As nucleus-forming phages become better characterized, understanding their unifying similarities and unique differences will help us understand how they occupy varied niches and infect diverse hosts. All identified nucleus-forming phages fall within the proposed Chimalliviridae family and share a core genome of 68 unique genes including chimallin, the major nuclear shell protein. A well-studied but non-essential protein encoded by many nucleus-forming phages is PhuZ, a tubulin homolog which aids in capsid migration, nucleus rotation, and nucleus positioning.
View Article and Find Full Text PDFiScience
May 2024
Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
With the recent resurgence of phage therapy in modern medicine, jumbophages are currently under the spotlight due to their numerous advantages as anti-infective agents. However, most significant discoveries to date have primarily focused on nucleus-forming jumbophages, not their non-nucleus-forming counterparts. In this study, we compare the biological characteristics exhibited by two genetically diverse jumbophages: 1) the well-studied nucleus-forming jumbophage, PhiKZ; and 2) the newly discovered non-nucleus-forming jumbophage, Callisto.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!