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 7–13 microM Fe to 1.1 micromol/g at 17–45 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