Table 1.
Product Distribution of AtTPS18 and Its Mutants.
| Mutations | Product distribution (%) |
Relative yield (-fold)c | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| aa | b | C | C3b | C4 | C5 | C6 | d | C7 | ||
| AtTPS18 (WT) | 0.15 | 0.01 | 2.8 | 0.6 | 1.3 | 3.2 | 0.8 | 6.1 | 85.1 | 1.0 |
| N493F | – | – | 2.6 | 0.65 | 2.4 | 4.2 | 1.2 | 7.8 | 81.2 | 0.4 |
| Y465A | 0.5 | 0.15 | 2.4 | 3.8 | 4.7 | 4.8 | 1.8 | 16.1 | 65.7 | 1.01 |
| G328P | 0.34 | – | 1.5 | 3.1 | 1.7 | 88.6 | 0.05 | 0.69 | 3.95 | 1.62 |
| G328A | 0.72 | – | 2.1 | 3.34 | 4.94 | 21.8 | 0.04 | 7.1 | 59.9 | 1.35 |
| G328S | 0.04 | – | 4.11 | 1.77 | 1.47 | 2.2 | 0.92 | 9.4 | 80.05 | 1.15 |
| G328C | 0.3 | – | 2.4 | 1.7 | 1.4 | 15.1 | 0.06 | 7.2 | 71.9 | 0.67 |
| G328L | – | – | – | 10.1 | 6.5 | 77.7 | – | – | 5.75 | 0.16 |
| G328N | 2.3 | – | – | 16.9 | 0.19 | – | 79.2 | – | 1.35 | 0.08 |
| F496S | 8.2 | 3.7 | – | 9.5 | 40.1 | – | 17.3 | 0.45 | 20.8 | 0.11 |
| F496M | 1.6 | 0.25 | 1.7 | 8.1 | 10 | 5.2 | 4.5 | 5.2 | 63.6 | 0.49 |
| F496H | 1.5 | – | 0.2 | 13.2 | 45.9 | – | 12.6 | 4.8 | 21.7 | 0.22 |
| F496A | – | 10.2 | – | 9.3 | 28.3 | – | 26.7 | 1.2 | 24.3 | 0.17 |
| F496C | 7.9 | 6.8 | 0.2 | 9.7 | 37.0 | 0.55 | 10.7 | 2.7 | 24.3 | 0.14 |
| G328A/F496A | 1.4 | 5.7 | 0.3 | 10.2 | 23.0 | 14.4 | 16.3 | 3.1 | 25.4 | 0.2 |
All product distributions were calculated from at least three independent experiments, whereas the results of F496S and F496A mutants were obtained from two replicates.
a
The structures of sesterterpenes a–d have not yet been determined.
b
The chemical structures of C3–C7 are shown in Figure 2.
c
The sum of the areas of the chromatogram peaks (GC–MS with SIM mode, m/z 340) of the main sesterterpenes produced by AtTPS18 and its mutants were calculated as the yield after normalization with an internal standard and culture density (OD600 value). The yield of AtTPS18 (wild type) was set to 1.0.