Table 1.
Enzymes of the 3-hydroxypropionate/4-hydroxybutyrate cycle in M. sedula
| Enzyme name | Label | ORF(s) | Reaction(s) Catalyzed | a Reference |
|---|---|---|---|---|
| Acetyl-CoA/Propionyl-CoA carboxylase | ACC | Msed_0147 Msed_0148 Msed_1375 |
a) Acetyl-CoA + HCO3− + ATP ↔ Malonyl-CoA + ADP + Pi b) Propionyl-CoA + HCO3− + ATP ↔ (S)-Methylmalonyl-CoA + ADP + Pi |
NP (Hugler et al., 2003) |
| Malonyl-CoA/Succinyl-CoA reductase (NADPH) | MCR | Msed_0709 | a) Malonyl-CoA + NADPH ↔ Malonic semialdehyde + NADP + CoA b) Succinyl-CoA + NADPH ↔ Succinic semialdehyde + NADP + CoA |
NCE (Kockelkorn and Fuchs, 2009) R (this work) R (S. tokodaii) (Alber et al., 2006) |
| Malonic semialdehyde reductase (NADPH) | MSR | Msed_1993 | Malonic semialdehyde + NADPH ↔ 3-Hydroxypropionate + NADP | R (Kockelkorn and Fuchs, 2009) |
| 3-Hydroxypropionyl-CoA synthetase (AMP-forming) | HPCS | Msed_1456 | 3-Hydroxypropionate + ATP + CoA ↔ 3-Hydroxypropionyl-CoA + AMP + PPi | NP, R (S. tokodaii) (Alber et al., 2008) R (this work) |
| 3-Hydroxypropionyl-CoA dehydratase | HPCD | Msed_2001 | a) 3-Hydroxypropionyl-CoA ↔ Acryloyl-CoA + H2O b) Crotonyl-CoA + H2O ↔ (S)-3-hydroxybutyryl-CoA |
NP (Teufel et al., 2009), R (this work) |
| Acryloyl-CoA reductase (NADPH) | ACR | Msed_1426 | Acryloyl-CoA + NADPH ↔ Propionyl-CoA + NADP | R (S. tokodaii) (Teufel et al., 2009) R (this work) |
| Methylmalonyl-CoA epimerase | MCE | Msed_0639 | (S)-Methylmalonyl-CoA ↔ (R)-Methylmalonyl-CoA | R (Marcheschi et al., 2012) |
| Methylmalonyl-CoA mutase | MCM | Msed_0638 | (R)-Methylmalonyl-CoA ↔ Succinyl-CoA | R (Marcheschi et al., 2012) |
| Msed_2055 | ||||
| Succinic semialdehyde reductase (NADPH) | SSR | Msed_1424 | Succinic semialdehyde + NADPH ↔ 4-Hydroxybutyrate + NADP | R (Kockelkorn and Fuchs, 2009, this work) |
| 4-Hydroxybutyryl-CoA synthetase (AMP-forming) | HBCS | Msed_0406 | a) 4-Hydroxybutyrate + ATP + CoA ↔4-Hydroxybutyryl-CoA + AMP + PPi b) 3-Hydroxypropionate + ATP + CoA ↔ 3-Hydroxypropionyl-CoA + AMP +PPi |
R (Hawkins et al., 2013) |
| 4-Hydroxybutyryl-CoA dehydratase | HBCD | Msed_1321 | 4-Hydroxybutyryl-CoA ↔ Crotonyl-CoA + H2O | R (Hawkins et al., 2014) |
| Crotonyl-CoA hydratase/(S)-3-Hydroxybutyryl-CoA dehydrogenase (NADH) | CCH/HBCD | Msed_0399 | a) Crotonyl-CoA + H2O ↔ (S)-3-Hydroxybutyryl-CoA b) (S)-3-Hydroxybutyryl-CoA + NAD ↔ Acetoacetyl-CoA + NADH |
NP (Ramos-Vera et al., 2011), R (Hawkins et al., 2014) |
| Acetoacetyl-CoA β-ketothiolase | AACT | Msed_0656 | Acetoacetyl-CoA + CoA ↔ 2 Acetyl-CoA | NP (Ramos-Vera et al., 2011), R (Hawkins et al., 2014) |
a
NCE = native cell extract; NP = native purified; R = recombinant purified