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Title: Small protein modules dictate prophage fates during polylysogeny
Abstract

Most bacteria in the biosphere are predicted to be polylysogens harbouring multiple prophages1–5. In studied systems, prophage induction from lysogeny to lysis is near-universally driven by DNA-damaging agents6. Thus, how co-residing prophages compete for cell resources if they respond to an identical trigger is unknown. Here we discover regulatory modules that control prophage induction independently of the DNA-damage cue. The modules bear little resemblance at the sequence level but share a regulatory logic by having a transcription factor that activates the expression of a neighbouring gene that encodes a small protein. The small protein inactivates the master repressor of lysis, which leads to induction. Polylysogens that harbour two prophages exposed to DNA damage release mixed populations of phages. Single-cell analyses reveal that this blend is a consequence of discrete subsets of cells producing one, the other or both phages. By contrast, induction through the DNA-damage-independent module results in cells producing only the phage sensitive to that specific cue. Thus, in the polylysogens tested, the stimulus used to induce lysis determines phage productivity. Considering the lack of potent DNA-damaging agents in natural habitats, additional phage-encoded sensory pathways to lysis likely have fundamental roles in phage–host biology and inter-prophage competition.

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Award ID(s):
2043238
NSF-PAR ID:
10498109
Author(s) / Creator(s):
; ; ; ; ; ;
Publisher / Repository:
Nature portfolio
Date Published:
Journal Name:
Nature
Volume:
620
Issue:
7974
ISSN:
0028-0836
Page Range / eLocation ID:
625 to 633
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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