Bacteriophage SP6 encodes a second tailspike protein that recognizes Salmonella enterica serogroups C2 and C3

By: Dana Gebhart, Steven R. Williams, & Dean Scholl | Source: Virology

SP6 is a <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/salmonella-phage” target=”_blank” rel=”noopener noreferrer”><em>salmonella phage</em></a> closely related to <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/coliphage” target=”_blank” rel=”noopener noreferrer”><em>coliphage</em></a> K1-5. K1-5 is notable in that it encodes two polysaccharide-degrading tailspike proteins, an endosialidase that allows it to infect <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/escherichia-coli” target=”_blank” rel=”noopener noreferrer”><em>E. coli</em></a> K1, and a <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/lyase” target=”_blank” rel=”noopener noreferrer”><em>lyase</em></a> that enables it to infect K5 strains. SP6 is similar to K1-5 except that it encodes a P22-like endorhamnosidase tailspike, gp46, allowing it to infect group B <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/salmonella” target=”_blank” rel=”noopener noreferrer”><em>Salmonella</em></a>. We show here that SP6 can also infect <em>Salmonella</em> <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/serotype” target=”_blank” rel=”noopener noreferrer”>serogroups </a>C<sub>2</sub> and C<sub>3</sub> and that a mutation in a putative second tailspike, gp47, eliminates this specificity. Gene 47 was fused to the coding region of the <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/amino-terminal-sequence” target=”_blank” rel=”noopener noreferrer”>N-terminal</a> portion of the <em><a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/pseudomonas-aeruginosa” target=”_blank” rel=”noopener noreferrer”>Pseudomonas aeruginosa</a></em> R2 <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/pyocin” target=”_blank” rel=”noopener noreferrer”>pyocin </a>tail fiber and expressed in trans such that the <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/fusion-protein” target=”_blank” rel=”noopener noreferrer”>fusion protein</a> becomes incorporated into pyocin particles. These pyocins, termed AvR2-SP47, killed serogroups C<sub>2</sub> and C<sub>3</sub> <em>Salmonella</em>. We conclude that SP6 encodes two tail proteins providing it a broad host range among <a href=”https://www.sciencedirect.com/topics/medicine-and-dentistry/salmonella-enterica-subsp-enterica” target=”_blank” rel=”noopener noreferrer”><em>Salmonella enterica</em></a>.