文章预览
Chestnut Studying 摘要 Bacteria defend against phage infection through a variety of antiphage defence systems. Many defence systems were recently shown to deplete cellular nicotinamide adenine dinucleotide (NAD+) in response to infection, by cleaving NAD+ into ADP-ribose (ADPR) and nicotinamide. It was demonstrated that NAD+ depletion during infection deprives the phage of this essential molecule and impedes phage replication. Here we show that a substantial fraction of phages possess enzymatic pathways allowing reconstitution of NAD+ from its degradation products in infected cells. We describe NAD+ reconstitution pathway 1 (NARP1), a two-step pathway in which one enzyme phosphorylates ADPR to generate ADPR pyrophosphate (ADPR-PP), and the second enzyme conjugates ADPR-PP and nicotinamide to generate NAD+. Phages encoding NARP1 can overcome a diverse set of defence systems, including Thoeris, DSR1, DSR2, SIR2–HerA and SEFIR, all of which deplete NAD+ as part of their de
………………………………
