TABLE 3.
Molecular and catalytic properties of 3-hydroxypropionyl-CoA synthetase from M. sedula and the recombinant enzyme from S. tokodaii
| Species | Substrates | Products | Specific activity (μmol min−1 mg−1)a | Apparent Km value (μM)b | Native molecular mass (kDa) | Subunit molecular mass (kDa) | Suggested composition | Turnover (per subunit) (s−1) | Specificity (%)c |
|---|---|---|---|---|---|---|---|---|---|
| M. sedula | 3-Hydroxypropionate, CoA, ATP | 3-Hydroxypropionyl-CoA, AMP, PPi | 18 | 3-Hydroxypropionate, 180; ATP, 45; CoA, NA | 340 | 78 | α4 | 23 | ATP, 100; UTP, 32; CTP, 13; ADP, 5; ITP, 3; GTP, <3; 3-hydroxpropionate, 100; propionate, 103; acrylate, 77; acetate, 42, butyrate, 20; 3-hydroxybutyrate, <1; crotonate, <1; glycerate, <1; malonate, <1 |
| S. tokodaii | 3-Hydroxypropionate, CoA, ATP | 3-Hydroxypropionyl-CoA, AMP, PPi | 6.7 | 3-Hydroxypropionate, 190; ATP, 110; CoA, NA | 140 | 74 | α2 | 8 | 3-Hydroxypropionate, 100; propionate, 98; acrylate, 96; acetate, 65; butyrate, 27; glycolate, 3; 3-mercaptopropionate, 36; 3-chloropropionate, 64; 3-hydroxybutyrate, <1; crotonate, <1; glycerate, <1; malonate, <1; β-alanine, <1; glycine, <1; succinate, <1; mesaconate, <1; methylsuccinate, <1 |
a
Activities were determined using the discontinuous enzyme assay at 65°C.
b
NA, not applicable (CoA dependency does not follow Michaelis-Menten kinetics).
c
The final concentrations of nucleotides were 3 mM each; the final concentrations of other substrates were 4 mM each.