Abstract
Like eukaryotic and archaeal viruses, which coopt the host's cellular pathways for their replication, bacteriophages have evolved strategies to alter the metabolism of their bacterial host. SPO1 bacteriophage infection of Bacillus subtilis results in comprehensive remodeling of cellular processes, leading to conversion of the bacterial cell into a factory for phage progeny production. A cluster of 26 genes in the SPO1 genome, called the host takeover module, encodes for potentially cytotoxic proteins that specifically shut down various processes in the bacterial host, including transcription, DNA synthesis, and cell division. However, the properties and bacterial targets of many genes of the SPO1 host takeover module remain elusive. Through a systematic analysis of gene products encoded by the SPO1 host takeover module, here we identified eight gene products that attenuated B. subtilis growth. Of the eight phage gene products that attenuated bacterial growth, a 25-kDa protein called Gp53 was shown to interact with the AAA+ chaperone protein ClpC of the ClpCP protease of B. subtilis. Our results further reveal that Gp53 is a phage-encoded adaptor-like protein that modulates the activity of the ClpCP protease to enable efficient SPO1 phage progeny development. In summary, our findings indicate that the bacterial ClpCP protease is the target of xenogeneic (dys)regulation by a SPO1 phage–derived factor and add Gp53 to the list of antibacterial products that target bacterial protein degradation and therefore may have utility for the development of novel antibacterial agents.
Highlights
Like eukaryotic and archaeal viruses, which coopt the host’s cellular pathways for their replication, bacteriophages have evolved strategies to alter the metabolism of their bacterial host
We wanted to identify genes in the SPO1 host takeover module that had a detrimental effect on B. subtilis growth by growing bacteria in the absence and presence of isopropyl 1-thio-
Under our conditions, plasmid-borne expression of Gp37, Gp41, Gp42, Gp44, Gp46, Gp53, Gp56, and Gp60 slowed the growth rate () to varying degrees but, in the cases of Gp37, Gp44, Gp53, Gp56, and Gp60, attenuated growth by extending the lag time preceding growth (Fig. 1D). It seemed that leaky expression of Gp53, Gp56, and Gp60 attenuated growth to some degree, indicating that the latter SPO1 gene products are potentially more toxic to B. subtilis than the others (i.e. Gp37, Gp41, Gp42, Gp44, and Gp46)
Summary
Like eukaryotic and archaeal viruses, which coopt the host’s cellular pathways for their replication, bacteriophages have evolved strategies to alter the metabolism of their bacterial host. With the exception of the product of gp, which has been postulated to interact with B. subtilis RNA polymerase [9, 10], the bacterial targets and mechanism of action of the gene products encoded by the host takeover module of SPO1 remain elusive. Phages and their gene products represent an underexploited resource for potentially developing novel antibacterial strategies and to gain new insights into bacterial cell function and regulation. We undertook a systematic approach to identify genes in the SPO1 phage host takeover module that had a detrimental effect on B. subtilis growth and unveil the biological role of the product of gp, which interacts with the Hsp100/Clp family member ClpC of B. subtilis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
