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HicA toxin without antitoxin

| posted 20 Mar, 2022 13:29
Hi All,
We've discussed in the past toxins, especially those that are bacteriostatic rather than bactericidal, can exist in phage genomes without a cognate anti-toxin. I can't remember where we ended up on this topic. The CR2 phage starstruck (stop 4760, gp7 in phamerator) has very strong HHpred data supporting a HicA toxin but there is no sign of an antitoxin. It doesn't make sense to me to call it "toxin in toxin/antitoxin system, HicA-like" if there it isn't a toxin/antitoxin system. Any thoughts on this?
| posted 20 Mar, 2022 14:31
Hi Sally,
I think I can call a toxin or antitoxin without its partner because the host may carry it. Curious if others agree.
Edited 20 Mar, 2022 14:31
| posted 21 Mar, 2022 19:09
Hi all,

I'm seeing exactly the same thing in a K4 phage (Ruthiejr): very strong HHPred hit to HicA toxin (99+% probability and 90% coverage) with no sign of an antitoxin. My recollection is the same as Debbie's: we can call either without the partner because it may not need it or the host may carry it. I'm leaving mine as "toxin in toxin/antitoxin system, HicA-like".
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