<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems"^^ . "Retrons are prokaryotic genetic systems containing reverse transcriptases (RTs) that\r\nproduce multiple copies of small single-stranded DNA (msDNA). Despite our\r\nunderstanding of the complex msDNA biosynthesis, the physiological role of retrons\r\nhas remained elusive. I established that the Retron-Sen2 in Salmonella Typhimurium\r\n(STm) encodes a toxin, which I have named RcaT (Retron cold-anaerobic Toxin).\r\nRcaT is activated when msDNA biosynthesis is perturbed and inhibits STm growth at\r\nambient temperatures or during anaerobiosis. The RT and msDNA are both necessary\r\nto counteract RcaT, by forming an RT-msDNA complex that inactivates RcaT through\r\ndirect protein-protein interactions. Thus, retrons constitute a novel family of tripartite\r\ntoxin/antitoxin systems (TAs), where the RcaT toxin is inactivated by the RT-msDNA\r\nantitoxin.\r\nBacteria carry dozens of TAs in their chromosomes. Normally, the antitoxin is coexpressed\r\nand neutralizes its cognate toxin, but TAs can be activated to inhibit\r\nbacterial growth. Yet, when and how TAs are triggered remains an enigma, hindering\r\nour understanding of their physiological roles. I developed TIC/TAC (Toxin\r\nInhibition/Activation Conjugation), a high-throughput reverse genetics approach, to\r\nsystematically identify molecular blockers and triggers of TAs. By applying TIC/TAC\r\nto Retron-Sen2, I identified multiple blockers and triggers of phage origin. Diverse\r\nphage proteins trigger RcaT toxicity by directly interacting with the msDNA-part of the\r\nantitoxin. Phage proteins can circumvent activation by directly blocking the activity of\r\nRcaT. I propose that retron-TAs act as abortive-infection anti-phage defense systems\r\nand delineate the mechanistic principles behind the retron-phage arms-race."^^ . "2022" . . . . . . . "Iakovos"^^ . "Bomponis"^^ . "Iakovos Bomponis"^^ . . . . . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems (PDF)"^^ . . . "Bomponis_PhD_Thesis.pdf"^^ . . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Bacterial retrons encode phage-sensing\r\ntoxin/antitoxin systems (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #31572 \n\nBacterial retrons encode phage-sensing \ntoxin/antitoxin systems\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .