Table 2.
The membrane-binding dehydrogenases in acetic acid bacteria based on their coenzyme differences.
| Category | Enzyme and code number | Substrate | Product | Subunita | Prosthetic group1b | Prosthetic group2b | Electron acceptorc |
|---|---|---|---|---|---|---|---|
| Quinoprotein-cytochrome complex | mADH (EC 1.1.1.1) | Ethanol | Acetaldehyde | I-II-III or I-II | PQQ | 4 heme c | UQ |
| Molybdoprotein-cytochrome complex | mALDH (EC 1.2.1.10) | Acetaldehyde | Acetic acid | II-III or I-II | MCD or PQQ | [2Fe-2S] and 3 heme c; [2Fe- 2S] and heme b; or heme b and c | UQ* |
| Flavoprotein-cytochrome complex | mGADH (EC 1.1.99.3) | d-Gluconic acid | 2-KGA | I-II-III | FAD | 3 heme c | UQ |
| m2-KGDH (EC 1.1.99.4) | 2-KGA | 2, 5-DKGA | I-II-III | FAD | 3 heme c | UQ* | |
| mFDH (EC 1.1.99.11) | d-Fructose | 5-KF | I-II-III | FAD | 3 heme c | UQ* | |
| mSLDH (EC 1.1.99.21) | d-Sorbitol | l-Sorbose | I-II-III | FAD | 3 heme c | UQ* | |
| Membrane-binding quinoprotein | mGDH (EC 1.1.99.17) | d-Glucose | GAL | I-II | PQQ | —d | UQ |
| mGLDH (EC 1.1.1.6) | Polyalcohol | Ketone | I-II | PQQ | — | UQ | |
| mQDH (EC 1.1.99.25) | Quinic acid | 3-DQA | I-II | PQQ | — | UQ | |
| mIDH (EC 1.1.1.18) | Myo-inositol | 2-Keto-myoinositol | I-II | PQQ | — | UQ* | |
| Other | mSDH (EC 1.1.99.12) | l-Sorbose | l-Sorbone | —4 | FAD | — | UQ |
| mSNDH (EC 1.1.1.-) | l-Sorbosone | 2-KGLA | — | NAD or NADP or PQQ | — | UQ* |
I-II-III: three subunits (large, medium-sized and small) complex; I-II: two subunits (large and medium-sized) complex.
Prosthetic groups 1 and 2 are involved in substrate oxidation and electron transfer.
UQ is experimentally verified by the experiments, and UQ* means that it has not been experimentally verified.
“—”: indicates that no such prosthetic group or subunit complex exists.
mADH, membrane-binding alcohol dehydrogenase; mALDH, membrane-binding acetaldehyde dehydrogenase; mGADH, membrane-binding gluconate dehydrogenase; m2-KGDH, membrane-binding 2-keto-d-gluconate dehydrogenase; mFDH, membrane-binding d-fructose dehydrogenase; mSLDH, membrane-bindingd-sorbitol dehydrogenase; mGDH, membrane-binding glucose dehydrogenase; mGLDH, membrane-binding glycerol dehydrogenase; mQDH, membrane-binding quinic acid dehydrogenase; mIDH, membrane-binding inositol dehydrogenase; [2Fe-2S], 2 iron-sulfur clusters; mSDH, membrane-binding sorbose dehydrogenase; mSNDH, membrane-binding sorbone dehydrogenase; 2-KGA, 2-keto-d-gluconic acid; 2, 5-DKGA, 2, 5-diketo-d-gluconic acid; 5-KF, 5-keto-d-fructose; GAL, gluconic acid-δ-lactone; 3-QDA, 3-dehydroquinic acid; 2-KGLA, 2-keto-l-gulonic acid; PQQ, pyrroloquinoline quinone; MCD, molybdenum-molybdopterin cytosine dinucleotide; FAD, flavin adenine dinucleotide; NAD, nicotinamide adenine dinucleotide; NADP, nicotinamide adenine dinucleotide phosphate; UQ, ubiquinone.