Trigger factor is a ribosome-associated molecular chaperone and is the first chaperone to interact with nascent polypeptide. Trigger factor can bind at the same time as the signal recognition particle (SRP), but is excluded by the SRP receptor (FtsY). The central domain of trigger factor has peptidyl-prolyl cis/trans isomerase activity. This protein is found in a single copy in virtually every bacterial genome. [Protein fate, Protein folding and stabilization]
Jiyao W et al.(2023). "The conserved domain database in 2023.",