Pyruvate:ferredoxin oxidoreductase PFOR

Figure 4.2 Reactions of pyruvate-processing enzymes pyruvate decarboxylase (PDC), p5Tuvate oxidase (POX), pyruvate ferredoxin oxidoreductase (PFOR) and pyruvate dehydrogenase (PDH). Their reactions diverge after the decarboxylation step. Pyr and PP represent 2,5-dimethyl-4-amino-pyrimidine and the ethyl diphosphate tail, respectively.

FIGURE 9.2 Physiology of ABE fermentation metabolism of Clostridium acetobutylicum with the respective enzymes and products. CoA, coenzyme A Ldh, lactate dehydrogenase Pdc, pyruvate decarboxylase Pfor, pyruvate ferredoxin oxidoreductase Fdred, ferredoxin reduced Thl, thiolase Hbd, p-hydroxybutyryl-CoA dehydrogenase Crt, crotonase Bed, butyryl-CoA dehydrogenase Etf, electron transfer flavoprotein Pta, phosphotransacetylase Ack, acetate kinase Ptb, phosphotransbutyrylase Buk, butyrate kinase Ctf A/B, acetoacetyl-CoA acyl-CoA transferase Adc, acetoacetate decarboxylase AdhE, aldehyde/alcohol dehydrogenase Bdh, butanol dehydrogenase. 

Several ThDP-dependent enzymes, e.g. pyruvate oxidase (POX) and pyr-uvate ferredoxin oxidoreductase (PFOR), form a transient radical intermediate after one-electron oxidation by neighbouring redox-active cofactors such as flavins (in the case of POX) and Fc4S4 clusters (in the case of PFOR) (Tittmann 2009). The radical intermediates are sometimes stable even at room... 

Figure 11.1 Hydrogen production pathway from glucose by fermentative microbes under anaerobic conditions. Dashed arrows indicate multiple enzymatic steps. PFOR, pymvate-ferredoxin oxidoreductase NFOR, NADH-ferredoxin oxidoreductase PFL, pyruvate formate lyase. Hydrogenases of different types are generally referred to as H2ase. ...

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