Table 3.
Catalytic and structural properties of AHAS from different organisms.a
| Organisms |
Subunits |
ApparentKmfor |
Specific activity (U/mg)b | Enzyme | Reference | ||||
|---|---|---|---|---|---|---|---|---|---|
| Catalytic | Regulatory | Pyruvate (mM) | TPP (µM) | Mg2+(µM) | FAD (µM) | ||||
| Mycobacterium avium | 66 | 18 | 2±0.2 | 7.5±0.4 | NR | 0.1 | 4 | R | [25] |
| Haemophilus influenza | 63 | NR | 9.2 | 13.6 | NR | NR | 1.5 | R | [28] |
| Shigella sonnei | 65 | NR | 8.1 | 0.01 | 180 | 0.12 | R | [27] | |
| Mycobacterium tuberculosis | NR | NR | 1.6±0.4 | 1.4±0.3 | NR | NR | 4.6 | R | [24] |
| Escherichia coli Isozyme I | 60.4 | 11.1 | 3.7 | NR | NR | 760 | 0.4 | R | [11], [64] |
| Escherichia coli Isozyme II | 59.3 | 9.6 | 5.0±0.5 2.6 | 0.65±0.03 1.1 | 0.01±0.002 3.8 | 0.17±0.04 NR | 20 52.7 | R | [65,17] |
| Escherichia coli Isozyme III | 63.0 | 17.5 | 11.5±1.4 | 18±3 | 3300±800 | 2.2±0.5 | 2.6 | R | [18], [19] |
| Saccharomyces cerevisiae | ~70 | 40 | 8.6±1.4 | 110 | 280 | 0.3 | 49±1.8 | R | [16] |
| Arabidopsis thalianac | 61 | NR | 11.7±0.6 | 25.3±1.4 | 198±19 | 1.5±0.22 | 7.9 | R | [29], [66] |
| Nicotiana tabacumc | NR | NR | 8.1–12.8 | 80-210 | NR | 1.4–2.6 | 2.8–3.4 | R | [67] |
| Bacillus stearothermophilusc | 62.4 | 18.7 | 8.8±1.2 | 5.5±0.8 | 20±3 | NR | 9.2 | R | [35] |
| Corynebacterium glutamicum | 67 | 15.4 | 8.4 | NR | NR | NR | 0.37 | N | [68], [69] |
| Methanococcus aeolicus | 65 | 19 | 6.8 | 1.6 | 300 | 1.3 | 39.3 | Nd R | [33], [54] |
| Haloferax volcanii | 50 | NR | 25.5±5 | 8.7±0.9 | NR | NR | 0.005 | N | [34] |
| Salmonella typhimurium | 59 | 9.7 | 10.6±0.7 | 1.5±0.2 | 22±4 | 0.8±0.1 | 25.3 | R | [20] |
| Thermotoga maritima | 65.5 | 20 | 16.4±1.9 | 56.5±5.6 | NR | 0.15±0.07 | 134±11 | R | This study |
a
NR: not reported; R, recombinant; N, native enzyme.
b
Expressed as µmoles of acetolactate produced per min per milligram of enzyme.
c
The kinetics parameters are only reported for the catalytic subunit.
d
The kinetic parameters are reported for the native protein.