TABLE 1.
Characteristics of the five candidate vaccine proteins
| Antigen-encoding gene | Function/ortholog | Range of TraDIS fitness scoresa | Size of full-length protein (no. of amino acids) | N-terminal signal peptide (amino acids)b | Protein subcellular localization predictionc | Conserved domain | No. of amino acids/molecular mass (kDa) of fusion proteind |
|---|---|---|---|---|---|---|---|
| SSU0185 | Putative tagatose-6-phosphate aldose/ketose isomerase (AgaS) | −4.66 to −8.58 (3/3) | 389 | Extracellular (literature mining) | 432/47.4 | ||
| SSU1215 | Putative surface-anchored dipeptidase | −0.90 to −10.22 (3/4) | 607 | 1–27 | Cell wall anchored (in silico) | LPSTG | 623/67.4 |
| SSU1355 | Putative surface-anchored 5′-nucleotidase | −0.81 to −8.23 (3/4) | 674 | 1–30 | Cell wall anchored (in silico) | LPNTG | 687/74.1 |
| SSU1773 | Putative surface-anchored serine protease | 1.00 to −8.74 (6/8) | 1,692 | 1–40 | Cell wall anchored (in silico) | LPQTG | 1695/187.4 |
| SSU1915 | Putative maltose/maltodextrin-binding protein precursor (Ma1X) | −5.03 to −5.05 (2/2) | 419 | Lipid anchored (in silico) | 462/49.0 |
TraDIS fitness scores are presented as the log2 fold change of the output/input determined by DESeq2 after normalization. The fraction of significantly attenuated mutants in each gene is shown in parentheses, using the parameters an input read of ≥500 and a P value of ≤0.05. Values in parentheses are the number of pigs with TraDIS fitness scores in the indicated range/total number of pigs tested.
Genes encoding the surface proteins were cloned without the N-terminal signal peptides.
In silico protein subcellular localization predictions by use of the PSORTb and LocateP databases.
The amino acid residues and molecular masses of pET-30 Ek/LIC fusion proteins were calculated by including the protein tag generated from the vector (43 amino acids, 4.8 kDa) and excluding the signal peptides, if present.