EC Number |
Cofactor |
Reference |
---|
4.2.1.167 | 4Fe-4S-center |
the enzyme contains [4F-4S] clusters |
733761 |
4.2.1.167 | Ferredoxin |
alternative electron donor besides flavodoxin is a two [4Fe-4S]1+/2+-cluster-containing ferredoxin, with redox potentials of 405 mV and 340mV. The flavodoxin is the dominant electron donor protein under iron-limiting conditions. The concentration of ferredoxin increases stepwise from about 0.2 micromol/g at 713 microM Fe to 1.1 micromol/g at 1745 microM Fe |
737565 |
4.2.1.167 | flavodoxin |
dominant electron donor protein under iron-limiting conditions |
737565 |
4.2.1.167 | riboflavin |
presence of trace amounts |
733770 |
4.2.1.167 | riboflavin 5'-phosphate |
1 mol per mol of heterodimeric dehydratase |
733770 |
4.2.1.167 | riboflavin 5'-phosphate |
the actual dehydration is mediated by component D, which contains 1.0 [4Fe-4S]2+ cluster, 1.0 reduced riboflavin-5'-phosphate and about 0.1 molybdenum (VI) per heterodimer |
737565 |
4.2.1.167 | riboflavin 5'-phosphate |
the enzyme contains 1.0 mol of riboflavin 5'-phosphate per mol of heterodimeric enzyme |
733766 |
4.2.1.167 | [4Fe-4S]-center |
each active component contains an oxygen sensitive diamagnetic [4Fe-4S]2+ cluster. Reduction of the [4Fe-4S]2+ cluster of the activator protein with dithionite yields a paramagnetic [4Fe-4S]1+ cluster with the unusual electron spin ground state S=3/2. Under air the activator protein looses its activity within seconds due to irreversible degradation of its [4Fe-4S]2+ cluster to a [2Fe-2S]2+ cluster. The [4Fe-4S]2+ cluster of the heterodimeric dehydratase cannot be reduced to a [4Fe-4S]1+ cluster |
733770 |
4.2.1.167 | [4Fe-4S]-center |
the actual dehydration is mediated by component D, which contains 1.0 [4Fe-4S]2+ cluster, 1.0 reduced riboflavin-5'-phosphate and about 0.1 molybdenum (VI) per heterodimer |
737565 |
4.2.1.167 | [4Fe-4S]-center |
the reduced [4Fe-4S]+ cluster containing activator protein transfers one electron to the dehydratase driven by ATP hydrolysis, which activates the enzyme. With a tenfold excess of titanium(III) citrate at pH 8.0 the activator can be further reduced, yielding about 50% of a superreduced [4Fe-4S]0 cluster in the all-ferrous state. The superreduced cluster has apparent spectroscopic similarities with the corresponding [4Fe-4S]0 cluster described for the nitrogenase Fe-protein. Only one-electron transfer steps are involved in dehydratase catalysis |
738706 |