Fig. 1

Schematic representation of the engineered pernisine genes subcloned into the pVF vector. The five plasmid constructs (pVFPER1-5) contained the pernisine mature domain and the C-terminal His₆-tag. Plasmid pVFPER1 contained the preproregion with the wild-type signal sequence from A. pernix (prepropernisine^WT). The other plasmids (pVFPER2-5) were codon-optimised, as: pVFPER2, prepropernisine^CO, with the proregion and the wild-type signal sequence from A. pernix; pVFPER3, propernisine^CO, with the wild-type signal sequence replaced by the srT signal sequence from S. rimosus; pVFPER4, with only the mature domain (pernisine^CO); and pVFPER5, with the mature domain (pernisine^CO) and the srT signal sequence from S. rimosus (i.e., fused directly to the core sequence of pernisine^CO). The enlarged boxes show the predicted signal peptidase cleavage sites between the wild-type signal sequence and the proregion of propernisine^WT/CO (a), the proregion and the mature protein (pernisine^WT/CO) (b), the S. rimosus srT signal sequence and the proregion (propernisine^CO) (c), and the srT signal sequence and the mature protein (pernisine^CO) (d). The Y-shaped lines show the predicted junctions between the different functional domains. The numbering of the positions of the selected amino acids is given