1.17.98.4: formate dehydrogenase (hydrogenase)
This is an abbreviated version!
For detailed information about formate dehydrogenase (hydrogenase), go to the full flat file.
Word Map on EC 1.17.98.4
-
1.17.98.4
-
fhl
-
hydrogenases
-
nife-hydrogenase
-
formate-dependent
-
hycb
-
selenopolypeptide
-
molybdoenzyme
-
h2-evolving
-
biohydrogen
-
h2-oxidizing
-
54-dependent
-
f0f1-atpase
- 1.17.98.4
- fhl
- hydrogenases
- nife-hydrogenase
-
formate-dependent
- hycb
-
selenopolypeptide
-
molybdoenzyme
-
h2-evolving
-
biohydrogen
-
h2-oxidizing
-
54-dependent
- f0f1-atpase
Reaction
Synonyms
benzylviologen-linked formate dehydrogenase, EC 1.1.99.33, EC 1.17.99.7, Fdh-H, FDH-O, fdhF gene product, FDHH, formate dehydrogenase (formate-hydrogen-lyase-linked), formate dehydrogenase H, formate dehydrogenase O, formate hydrogenlyase, methylviologen-dependent formate dehydrogenase, molybdenum-containing formate dehydrogenase H
ECTree
1.17.98.4 formate dehydrogenase (hydrogenase)Advanced search results
results (
results (Metals Ions
Metals Ions on EC 1.17.98.4 - formate dehydrogenase (hydrogenase)
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
top
METALS and IONS 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
Fe
Mo
Se
selenium
-
anaerobic oxidation of formate by Methanococcus vannielii is catalyzed by two readily separable formate dehydrogenases. One of these is a 105000 Da protein that contains molybdenum, iron, and acid-labile sulfide, but not selenium. The other is a high molecular weight complex composed of selenoprotein and molybdo-iron sulfur protein subunits
Fe
-
Mo(IV)- and the reduced FeS cluster-containing form of the enzyme is crystallized and this can be converted into Mo(VI)- and oxidized FeS cluster form upon oxidation
Fe
-
oxidation of Mo(IV) centers by the Fe4S4 is used for deprotonation of YH(formate) and transfer of the formate proton H+(formate) against the thermodynamic potential. The Mo-Se bond is estimated to be covalent to the extent of 17-27% of the unpaired electron spin density residing in the valence 4s and 4p selenium orbitals, based on comparison of the scalar and dipolar hyperfine components to atomic 77Se. Two electron oxidation of formate by the Mo(VI) state converts Mo to the reduced Mo(IV) state with the formate proton, H+(formate), transferring to a nearby base Y-. Transfer of one electron to the Fe4S4 center converts Mo(IV) to the EPR detectable Mo(V) state. The Y- is located within magnetic contact to the [Mo-Se] center, as shown by its strong dipolar 1Hf hyperfine couplings. Photolysis of the formate-induced Mo(V) state abolishes the 1Hf hyperfine splitting from YH(formate), suggesting photoisomerization of this group or phototransfer of the proton to a more distant proton acceptor group A-. The minor effect of photolysis on the 77Se-hyperfine interaction with [77Se] selenocysteine suggests that the Y- group is not the Se atom, but instead might be the imidazole ring of the His141 residue which is located in the putative substrate-binding pocket close to the [Mo-Se] center. It is proposed that the transfer of 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
Fe
-
the reinterpretation of the crystal structure suggests a new reaction mechanism: In step I, formate binds directly to Mo, displacing Se-Cys140. In step II, the alpha-proton from formate may be transferred to the nearby His141 that acts as general base. In this step the CO2 molecule can be released and two electrons transferred to Mo. Alternatively, step II may involve a selenium-carboxylated intermediate. In step III, electrons from Mo(IV) are transferred via the [4Fe-4S] center to an external electron acceptor and the catalytic cycle is completed
Mo
-
enzyme contains a bis-molybdopterin guanine dinucleotide cofactor. EPR spectroscopy of the Mo(V) state indicates a square pyramidal geometry analogous to that of the Mo(IV) center. The strongest ligand field component is likely the single axial Se atom producing a ground orbital configuration Mo(dxy). The Mo-Se bond is estimated to be covalent to the extent of 17-27% of the unpaired electron spin density residing in the valence 4s and 4p selenium orbitals, based on comparison of the scalar and dipolar hyperfine components to atomic 77Se. Two electron oxidation of formate by the Mo(VI) state converts Mo to the reduced Mo(IV) state with the formate proton, H+(formate), transferring to a nearby base Y-. Transfer of one electron to the Fe4S4 center converts Mo(IV) to the EPR detectable Mo(V) state. The Y- is located within magnetic contact to the [Mo-Se] center, as shown by its strong dipolar 1Hf hyperfine couplings. Photolysis of the formate-induced Mo(V) state abolishes the 1Hf hyperfine splitting from YH(formate), suggesting photoisomerization of this group or phototransfer of the proton to a more distant proton acceptor group A-. The minor effect of photolysis on the 77Se-hyperfine interaction with [77Se] selenocysteine suggests that the Y- group is not the Se atom, but instead might be the imidazole ring of the His141 residue which is located in the putative substrate-binding pocket close to the [Mo-Se] center. It is proposed that the transfer of 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
Mo
-
Mo(IV)- and the reduced FeS cluster-containing form of the enzyme is crystallized and this can be converted into Mo(VI)- and oxidized FeS cluster form upon oxidation
Mo
-
molybdopterin containg enzyme, Mo is coordinated with the Se atom of selenocysteine
Mo
-
the reinterpretation of the crystal structure suggests a new reaction mechanism: In step I, formate binds directly to Mo, displacing Se-Cys140. In step II, the alpha-proton from formate may be transferred to the nearby His141 that acts as general base. In this step the CO2 molecule can be released and two electrons transferred to Mo. Alternatively, step II may involve a selenium-carboxylated intermediate. In step III, electrons from Mo(IV) are transferred via the [4Fe-4S] center to an external electron acceptor and the catalytic cycle is completed
Se
-
formate dehydrogenase H contains selenocysteine as an integral amino acid. Selenium of formate dehydrogenase H is directly involved in formate oxidation
Se
-
Mo of the molybdopterin is coordinated with the Se atom of selenocysteine
Se
-
selenocysteine-containing enzyme. The molybdenum-coordinated selenocysteine is essential for catalytic activity of the native enzyme
Se
-
the enzyme contains selenocysteine. The Mo-Se bond is estimated to be covalent to the extent of 17-27% of the unpaired electron spin density residing in the valence 4s and 4p selenium orbitals, based on comparison of the scalar and dipolar hyperfine components to atomic 77Se. Two electron oxidation of formate by the Mo(VI) state converts Mo to the reduced Mo(IV) state with the formate proton, H+(formate), transferring to a nearby base Y-. Transfer of one electron to the Fe4S4 center converts Mo(IV) to the EPR detectable Mo(V) state. The Y- is located within magnetic contact to the [Mo-Se] center, as shown by its strong dipolar 1Hf hyperfine couplings. Photolysis of the formate-induced Mo(V) state abolishes the 1Hf hyperfine splitting from YH(formate), suggesting photoisomerization of this group or phototransfer of the proton to a more distant proton acceptor group A-. The minor effect of photolysis on the 77Se-hyperfine interaction with [77Se] selenocysteine suggests that the Y- group is not the Se atom, but instead might be the imidazole ring of the His141 residue which is located in the putative substrate-binding pocket close to the [Mo-Se] center. It is proposed that the transfer of 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
Se
-
the enzyme contains selenocysteine.The trxB gene is required for the formation of selenocysteine containing FDHH polypeptide
Se
-
the fdhF gene of Escherichia coli codes for the selenocysteine-including protein subunit of formate dehydrogenase H
Se
-
the reinterpretation of the crystal structure suggests a new reaction mechanism: In step I, formate binds directly to Mo, displacing Se-Cys140. In step II, the alpha-proton from formate may be transferred to the nearby His141 that acts as general base. In this step the CO2 molecule can be released and two electrons transferred to Mo. Alternatively, step II may involve a selenium-carboxylated intermediate. In step III, electrons from Mo(IV) are transferred via the [4Fe-4S] center to an external electron acceptor and the catalytic cycle is completed
