Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NADH-cytochrome c reductase, a component of benzoate 1,2-dioxygenase system, was purified to homogeneity, as judged by sodium dodecyl sulfate disc gel electrophoresis and ultracentrifugation, from benzoate-induced cells of Pseudomonas arvilla. The molecular weight of the enzyme was determined to be 38,300 by sedimentation equilibrium analysis, 37,000 by Sephadex G-100 gel filtration, and 37,500 by sodium dodecyl sulfate disc gel electrophoresis, respectively, indicating that the enzyme consisted of a single polypeptide chain. The sedimentation coefficient was calculated to be 3.3 S. The Stokes radius for the enzyme was calculated to be 27 A. The isoelectric point of the enzyme was estimated to be pH 4.2. The enzyme contained 1 mol of FAD, 2 mol of iron, and 2 mol of labile sulfide/mol of enzyme. It exhibited absorption spectrum with maxima at 273, 340, 402, and 467 nm. Amino acid analysis of the enzyme revealed that it was devoid of tryptophan. The enzyme contained 9 mol of cysteine/mol of enzyme but no disulfide linkage. The turnover number of the enzyme for the NADH-dependent reduction of cytochrome c was 17,100 at 24 degrees C. Although NADPH also acted as an electron donor, NADH was highly superior to NADPH. Ferricyanide and 2,6-dichlorophenolindophenol served as electron acceptors. Certain other properties of the enzyme are also presented.
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PMID:Characterization of NADH-cytochrome c reductase, a component of benzoate 1,2-dioxygenase system from Pseudomonas arvilla c-1. 21 33

The catabolic genes necessary for the conversion of benzoate to catechol have been cloned from Acinetobacter calcoaceticus into Escherichia coli. The cloned genes, benABCD, encoded both a benzoate 1,2-dioxygenase system, composed of NADH-cytochrome c reductase and terminal oxygenase components, and a cis-diol dehydrogenase. The dioxygenase system appears to be encoded by three genes, benABC, whose products, 53-, 19-, and 38-kilodalton proteins, correspond in size to those of components in other bacterial dioxygenases. The cloned dioxygenase system is expressed at high level in E. coli, enabling the conversion of benzoate to a cis-diol, 2-hydro-1,2-dihydroxybenzoate, at a rate comparable to that of fully induced A. calcoaceticus cultures. A cis-diol dehydrogenase, the product of the A. calcoaceticus benD gene, when present in E. coli enables this organism to convert the cis-diol intermediate to catechol. The dehydrogenase has been partially purified and is a dimer with two identical 31-kilodalton subunits. The ben genes are clustered on the A. calcoaceticus chromosome with independently regulated genes needed for the dissimilation of catechol. In a 16-kilobase-pair region of the chromosome there are 10 genes for benzoate catabolism, organized in no fewer than three transcriptional units. This kind of arrangement, termed supraoperonic clustering, has been observed previously in pseudomonads.
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PMID:Cloning and expression in Escherichia coli of Acinetobacter calcoaceticus genes for benzoate degradation. 282 37

NADH-cytochrome c reductase, a component of benzoate 1,2-dioxygenase system, is an ion-sulfur flavoprotein with one FAD and one iron-sulfur cluster of [2Fe-2S] type (Yamaguchi, M., and Fujisawa, H. (1978) J. Biol. Chem. 253, 8848-8853). Treatment of NADH-cytochrome c reductase with p-chloromercuriphenylsulfonic acid resulted in fading of its color with a concomitant loss of the NADH-cytochrome c reductase activity. The p-chloromercuriphenylsulfonic acid-treated enzyme was found to contain one FAD but no significant amounts of iron and labile sulfide. Incubation of the iron-sulfur-depleted enzyme with ferrous ions and sulfide in the presence of 2-mercaptoethanol led to both reconstitution of iron-sulfur cluster of the enzyme and concomitant restoration of the enzyme activity. Although the iron-sulfur-depleted enzyme catalyzed NADH-dependent reduction of ferricyanide, nitroblue tetrazolium, or oxygen, it could not catalyze NADH-dependent reduction of the oxygenase component of benzoate 1,2-dioxygenase system. In contrast, the reconstituted enzyme recovered the activity of NADH-dependent reduction of the oxygenase component to the original level. Certain other catalytic and molecular properties of the iron-sulfur-depleted enzyme and the reconstituted enzyme are also presented.
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PMID:Reconstitution of iron-sulfur cluster of NADH-cytochrome c reductase, a component of benzoate 1,2-dioxygenase system from Pseudomonas arvilla C-1. 724 Feb 44

The benzoate 1,2-dioxygenase system of Pseudomonas arvilla consists of two proteins, an NADH-cytochrome c reductase and an oxygenase. The oxygenase component was purified to apparent homogeneity by the criteria of polyacrylamide gel electrophoresis from benzoate-induced cells of P. arvilla. The molecular weight of the enzyme was determined to be 273,000 by sedimentation equilibrium analysis, 280,000 by electrophoresis on polyacrylamide gels of different concentrations, and 270,000 by Sepharose CL-6B gel filtration, respectively. The sedimentation coefficient, the Stokes radius, and the partial specific volume of the enzyme were calculated to be 10.0 S, 56 A, and 0.72 ml/g, respectively. The isoelectric point of the enzyme was estimated to be pH 4.5. The enzyme contained about 10 mol of iron and about 8 mol of labile sulfide/mol of enzyme. The iron-sulfur clusters of the enzyme were suggested to be (2Fe-2S*) from cluster-extrusion experiments (S*, sulfide, acid-labile sulfur). No significant amounts of heme or flavin were detected in the enzyme. The enzyme exhibited absorption spectrum with maxima at 279, 325, and 464 nm. The turnover number of the enzyme in the presence of saturating amounts of NADH-cytochrome c reductase, the other component of the benzoate 1,2-dioxygenase system, was calculated to be 22,000 at 24 degrees C. The apparent Km values for the reductase, benzoate, and molecular oxygen were 26 (0.97 mg of protein/ml), 3.9, and 4.3 microM, respectively.
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PMID:Purification and characterization of an oxygenase component in benzoate 1,2-dioxygenase system from Pseudomonas arvilla C-1. 737 24

The bopXYZ genes from the gram-positive bacterium Rhodococcus sp. strain 19070 encode a broad-substrate-specific benzoate dioxygenase. Expression of the BopXY terminal oxygenase enabled Escherichia coli to convert benzoate or anthranilate (2-aminobenzoate) to a nonaromatic cis-diol or catechol, respectively. This expression system also rapidly transformed m-toluate (3-methylbenzoate) to an unidentified product. In contrast, 2-chlorobenzoate was not a good substrate. The BopXYZ dioxygenase was homologous to the chromosomally encoded benzoate dioxygenase (BenABC) and the plasmid-encoded toluate dioxygenase (XylXYZ) of gram-negative acinetobacters and pseudomonads. Pulsed-field gel electrophoresis failed to identify any plasmid in Rhodococcus sp. strain 19070. Catechol 1,2- and 2,3-dioxygenase activity indicated that strain 19070 possesses both meta- and ortho-cleavage degradative pathways, which are associated in pseudomonads with the xyl and ben genes, respectively. Open reading frames downstream of bopXYZ, designated bopL and bopK, resembled genes encoding cis-diol dehydrogenases and benzoate transporters, respectively. The bop genes were in the same order as the chromosomal ben genes of P. putida PRS2000. The deduced sequences of BopXY were 50 to 60% identical to the corresponding proteins of benzoate and toluate dioxygenases. The reductase components of these latter dioxygenases, BenC and XylZ, are 201 residues shorter than the deduced BopZ sequence. As predicted from the sequence, expression of BopZ in E. coli yielded an approximately 60-kDa protein whose presence corresponded to increased cytochrome c reductase activity. While the N-terminal region of BopZ was approximately 50% identical in sequence to the entire BenC or XylZ reductases, the C terminus was unlike other known protein sequences.
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PMID:Cloning and expression of the benzoate dioxygenase genes from Rhodococcus sp. strain 19070. 1137 57