Table 2. Results of cell complementation tests for ThyA-negative E. coli FE013 (pQE80L) as a control, and for pQE80L expressing the WT TS (E. coli_WT), the E. coli double mutant G23K/E86K (E. coli_2K), and the E. coli quadruple mutant G23K/E82K/E86K/G257K TS (E. coli_4K), see Fig. S3.
| Strain | Without IPTG | With IPTG |
|---|---|---|
| FE013 (pQE80L) | – | – |
| FE013 (pQE80L_E. coli_WT) | ++§ | +++ |
| FE013 (pQE80L_E. coli_2K) | +/−§ | + |
| FE013 (pQE80L_E. coli_4K) | – | – |
§Complementation of the E. coli ΔthyA strain under the conditions of leaky expression in the absence of the IPTG inducer was observed for the wild type thyA gene and, to a very limited extent, for the double mutant thyA gene. Furthermore, complementation was observed for all single lysine mutants under similar conditions of leaky expression (data not shown).