Time-resolved DNA release from an O-antigen specific Salmonella bacteriophage with a contractile tail

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Item Type:	Article
Title:	Time-resolved DNA release from an O-antigen specific Salmonella bacteriophage with a contractile tail
Creators Name:	Broeker, N.K., Roske, Y., Valleriani, A., Stephan, M.S., Andres, D., Koetz, J., Heinemann, U. and Barbirz, S.
Abstract:	Myoviruses, bacteriophages with T4-like architecture, must contract their tails prior to DNA release. However, quantitative kinetic data on myovirus particle opening are lacking, although they are promising tools in bacteriophage-based antimicrobial strategies directed against Gram-negative hosts. For the first time, we show time-resolved DNA ejection from a bacteriophage with a contractile tail, the multi-O-antigen specific Salmonella myovirus Det7. DNA release from Det7 was triggered by lipopolysaccharide (LPS) O-antigen receptors and notably slower than in non-contractile tailed siphoviruses. Det7 showed two individual kinetic steps for tail contraction and particle opening. Our in vitro studies showed that highly specialized tailspike proteins (TSPs) are necessary to attach the particle to LPS. A P22-like TSP confers specificity for the S. Typhimurium O-antigen. Moreover, crystal structure analysis at 1.63 Å resolution confirmed that Det7 recognized the S. Anatum O-antigen via an ε15-like TSP, DettilonTSP. DNA ejection triggered by LPS from either host showed similar velocities, particle opening is thus a process independent of O-antigen composition and the recognizing TSP. In Det7, at permissive temperatures TSPs mediate O-antigen cleavage and couple cell surface binding with DNA ejection, but no irreversible adsorption occurred at low temperatures. This finding was in contrast to short-tailed Salmonella podoviruses, illustrating that tailed phages use common particle opening mechanisms, but have specialized into different infection niches.
Keywords:	Salmonella Myovirus, Contractile Tail, Lipopolysaccharide, DNA ejection, O-Antigen Specificity, Tailspike Protein, Bacteriophage, Molecular Machine
Source:	Journal of Biological Chemistry
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Volume:	294
Number:	31
Page Range:	11751-11761
Date:	2 August 2019
Official Publication:	https://doi.org/10.1074/jbc.RA119.008133
External Fulltext:	View full text on PubMed Central
PubMed:	View item in PubMed

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