Identification of the gene encoding NADH-rubredoxin oxidoreductase in Clostridium acetobutylicum.
NADH-rubredoxin oxidoreductase (NROR), a flavoprotein from the obligately anaerobe Clostridium acetobutylicum is encoded by an ORF (nror) of 1140 nucleotides. Whereas primary structure analysis reveals that NROR has amino acid sequence patterns homologous with those involved in FAD and NAD-binding, the enzyme is distantly related to other flavoproteins in the databank. NROR is highly active for reducing clostridial rubredoxin (Rd) especially against C. acetobutylicum Rd with an efficiency (k(cat)/K(m)) of 400,000 mM(-1)s(-1). These results suggest that Rd from C. acetobutylicum, C. pasteurianum, C. butyricum, and C. cellulolyticum can be interchanged with each other. Since C. acetobutylicum is the sole Clostridium strain that possesses such an enzyme, possible functions are discussed with regard to Desulfovibrio gigas and Pyrococcus furiosus, the only two other anaerobic systems for which a similar activity was reported, but no gene isolated.
Guedon
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Laboratoire de Biochimie des Bactéries Gram+, Université Henri Poincaré, Faculté des Sciences, BP 239, 54506 Vandoeuvre-lès-Nancy Cédex, France.
Petitdemange
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D000244:Adenosine Diphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001665:Binding Sites; D003013:Clostridium / Q000201:enzymology* / Q000235:genetics*; D003901:Desulfovibrio / Q000201:enzymology; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D016366:Open Reading Frames; D010084:Oxidation-Reduction; D020027:Pyrococcus furiosus / Q000201:enzymology; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012416:Rubredoxins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D011994:Recombinant Proteins; D012416:Rubredoxins; D005182:Flavin-Adenine Dinucleotide; D009249:NADP; D000244:Adenosine Diphosphate; C023091:rubredoxin-NAD+ reductase; D009247:NADH, NADPH Oxidoreductases