Fig. 4

Schematic diagram of the candidate construct. The epitope‑rich domains of PhtD, PsaA, and PspC are shown in green, red, and turquoise blue, respectively, which are linked together with GGSSGG. The truncated fragment of PepO shown in yellow as a potential adjuvant candidate was joined to the N-terminal of the considered domains through the EAAAK linker. A hexa-histidine (His6) tag was fused at the C-terminal of the candidate vaccine to facilitate purification