EC Number   |
Natural Substrates |
|---|
    1.17.98.4 | formate + acceptor |
formate dehydrogenase H (FDHH) catalyses the first step in the formate hydrogen lyase (FHL) system |
| 1.17.98.4 | formate + acceptor |
the transfer of the formate proton, H+(formate), from formate to the active site base Y- is thermodynamically coupled to two-electron oxidation of the formate molecule, thereby facilitating formation of CO2. Under normal physiological conditions, when electron flow is not limited by the terminal acceptor of electrons, the energy released upon oxidation of Mo(IV) centers by the Fe4S4 is used for deprotonation of YH(formate) and transfer of H+(formate) against the thermodynamic potential. This mechanism of proton release from FDH(Se) may play a physiological role in delivery of the formate proton H+(formate) to hydrogenase 3, which is the natural terminal acceptor of electrons for FDH(Se) |
| 1.17.98.4 | formate + benzyl viologen |
the enzyme may have a role in formate reuptake |
| 1.17.98.4 | formate + HycB |
the hydrogenase 3 Fe-S subunit HycB may represent the electron transfer partner of FDH-H |
| 1.17.98.4 | formate + oxidized coenzyme F420 |
- |
| 1.17.98.4 | formate + [NiFe]-hydrogenase 3 |
- |
| 1.17.98.4 | more |
Escherichia coli possesses two hydrogenases, Hyd-3 and Hyd-4. These, in conjunction with formate dehydrogenase H (Fdh-H), constitute distinct membrane-associated formate hydrogenlyases, FHL-1 and FHL-2, both catalyzing the decomposition of formate to H2 and CO2 during fermentative growth. FHL-1 is the major pathway at acidic pH. At alkaline pH formate increases an activity of Fdh-H and of Hyd-3 both but not of Hyd-4 |
| 1.17.98.4 | more |
hydrogenase 3 but not hydrogenase 4 is the major enzyme in hydrogen gas production by Escherichia coli formate hydrogenlyase at acidic pH and in the presence of external formate |
| 1.17.98.4 | more |
physiological role of FSH-O is to ensure rapid adaptation during a shift from aerobiosis to anaerobiosis |
