The role of antimicrobial peptides in the evolution of endosymbiotic protein import

First proposed in 1993 based on a screen for mutants sensitive to antimicrobial peptides (sap) in Salmonella [4], RAMP internalization was finally confirmed via immunogold labeling for sap homologues in non-typeable Haemophilus influenzae [5]. [...]domains include cleavage sites (mTP and cTP, indicated by scissors), an uncharged N-terminus (cTP) with a leading Phenylalanine (F) in basal algal lineages, or a long carboxyl terminus (crTP) with a second predicted amphipathic helix carrying both positive and negative charges (–+). https://doi.org/10.1371/journal.ppat.1009466.g001 The amoeba Paulinella provides a further example of TPs, having acquired a photosynthetic organelle called chromatophore in a much more recent cyanobacterial endosymbiosis (ca. 60 to 100 Mya) than Archaeplastida (ca. 1 Gya) [17,18]. Having a system of protein import was crucial to enable the large-scale endosymbiotic gene transfer from the emerging organelles to the host nucleus. Molecular genetic analysis of a locus required for resistance to antimicrobial peptides in Salmonella typhimurium.