TABLE 2.
Growth allowed by ApbC variants
Doubling times were calculated using the formulas μ = ln(X/X0)/T, where μ is the growth rate; X and Xo are absorbance at 650 nm; T(h) is the time between absorbance readings X and Xo; and doubling time (g) = (ln 2)/μ (79). Numbers represent the average of three independent cultures.
|
Relevant chromosomal genotype
| |||||
|---|---|---|---|---|---|
|
ApbC variant
|
apbC yggX
|
purF apbC
|
|||
| Glua | Glu + Thi | TC + Thi | Glcn + Adn | Glcn + Adn + Thi | |
| Vector | NG (0.33)b | 2.5 ± 0.32 | NG (0.21) | NG (0.16) | 1.5 ± 0.07 |
| Wild type | 1.6 ± 0.03 | 1.7 ± 0.16 | 2.7 ± 0.26 | 2.4 ± 0.28 | 1.6 ± 0.08 |
| ApbC(C70A) | 1.7 ± 0.17 | 1.6 ± 0.06 | 3.1 ± 0.54 | 2.0 ± 0.02 | 1.4 ± 0.04 |
| ApbC(K116A) | NG (0.25) | 1.8 ± 0.12 | NG (0.24) | NG (0.18) | 1.7 ± 0.26 |
| ApbC(K121A) | NG (0.31) | 2.2 ± 0.10 | NG (0.19) | NG (0.10) | 2.1 ± 0.24 |
| ApbC(S122A) | NG (0.27) | 2.3 ± 0.16 | NG (0.15) | NG (0.12) | 1.9 ± 0.09 |
| ApbC(S182A) | 2.7 ± 0.09 | 1.7 ± 0.08 | NG (0.28) | 2.4 ± 0.15 | 1.5 ± 0.24 |
| ApbC(C283A) | NG (0.27) | 2.5 ± 0.12 | NG (0.19) | NG (0.15) | 1.6 ± 0.16 |
| ApbC(C286A) | NG (0.23) | 2.4 ± 0.22 | NG (0.20) | NG (0.18) | 1.6 ± 0.04 |
a
Abbreviations used are as follows: Glu, glucose; Thi, thiamine; TC, tricarballylate, Glcn, gluconate; Adn, adenine.
b
NG, no growth was determined when strains showed doubling times of greater than 6 h and/or a final A650 less than 0.35. Average final A650 is indicated in parentheses for strains determined as no growth.