Table 1. Escherichia coli strains and plasmids used in the study.
| Strains | Relevant properties | Plasmid | Reference |
|---|---|---|---|
| BL21 | B F - , ompT, hsdS (rB -, mB -), gal, dcm. | GE Healthcare | |
| 8751 | LTR192G-STaP13F, BL21/pfusion-2b | LT192-L-STa13/pET28α | [22] |
| 8752 | STaP13F-LTR192G, BL21/pfusion-3b | STa13-gly-pro-LT192/pET28α | [22] |
| 8753 | LTR192GA1-STaP13F-LTA2-B, BL21/pfusion-4b | LT192A1-gly-pro-STa13-LTA2-B/pET28α | [22] |
| TOP10 | F- mcrAΔ(mrr-hsdRMS-mcrBC) Φ80lacZΔM15 ΔlacX74 recA1 deoR araD139Δ(ara-leu)7697 galU galK rpsL (StrR)endA1 nupG | Invitrogen | |
| 8325 | STa recombinant strain, TOP10 | STa in pBR322 | [23] |
| 8407 | pSTaA14Q mutant strain, TOP10 | STaA14Q in pBR322 | this study |
| 8460 | LT recombinant strain, TOP10 | LT in pBR322 | [22] |
| 8543 | LTR192G mutant strain, TOP10 | LTR192G in pBR322 | [22] |
| 9123 | LTS63K mutant strain, TOP10 | LTS63K in pBR322 | this study |
| 9125 | LTS63K/R192G mutant strain, TOP10 | LTS63K/R192G in pBR322 | this study |
| 9078 | LTR192G/L211A mutant strain, TOP10 | LTR192G/L211A in pBR322 | this study |
| 9127 | LTS62K/R192G/L211A mutant strain, TOP10 | LTS62K/R192G/L211A in pBR322 | this study |
| 9157 | p3xSTaA14Q-tmLT plasmid*, TOP10 | 3xSTaA14Q-tmLT in pET28α | this study |
| 9164 | p9157, BL21 | 3xSTaA14Q-tmLT in pET28α | this study |
| 8955 | Negative control, BL21/pET28α | pET28α | [23] |
*: Nucleotides coding the transmembrane signal peptides of the mutated eltA, eltB and estA genes, and the stop codons of the eltA, eltB, & the firs 2 copies of estA were removed to construct the fusion as a single open reading frame.