The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
Josa Marie Wehrfritz - One of the best experts on this subject based on the ideXlab platform.
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the biochemical characterization of a novel non haem iron Hydroxylamine Oxidase from paracoccus denitrificans gb17
Biochemical Journal, 1996Co-Authors: James W B Moir, Josa Marie Wehrfritz, Stephen Spiro, D J RichardsonAbstract:The characterization of the Hydroxylamine Oxidase from the heterotrophic nitrifier Paracoccus denitrificans GB17 indicates the enzyme to be entirely distinct from the Hydroxylamine Oxidase from the autotrophic nitrifier Nitrosomonas europaea. Hydroxylamine Oxidase from P. denitrificans contains three to five non-haem, non-iron-sulphur iron atoms as prosthetic groups, predominantly co-ordinated by carboxylate ligands. The interaction of the enzyme with the electron-accepting proteins cytochrome C556 and pseudoazurin is mainly hydrophobic. The catalytic mechanism of Hydroxylamine Oxidase from P. denitrificans is different from the enzyme from N. europaea because the production of nitrite by the former requires molecular oxygen. Under anaerobic conditions the enzyme makes nitrous oxide as a sole product.
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Purification of Hydroxylamine Oxidase from Thiosphaera pantotropha. Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification.
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, David J RichardsonAbstract:Abstract Thiosphaera pantotropha , a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C 551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
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purification of Hydroxylamine Oxidase from thiosphaera pantotropha identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, D J RichardsonAbstract:Thiosphaera pantotropha, a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome c551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
D J Richardson - One of the best experts on this subject based on the ideXlab platform.
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the biochemical characterization of a novel non haem iron Hydroxylamine Oxidase from paracoccus denitrificans gb17
Biochemical Journal, 1996Co-Authors: James W B Moir, Josa Marie Wehrfritz, Stephen Spiro, D J RichardsonAbstract:The characterization of the Hydroxylamine Oxidase from the heterotrophic nitrifier Paracoccus denitrificans GB17 indicates the enzyme to be entirely distinct from the Hydroxylamine Oxidase from the autotrophic nitrifier Nitrosomonas europaea. Hydroxylamine Oxidase from P. denitrificans contains three to five non-haem, non-iron-sulphur iron atoms as prosthetic groups, predominantly co-ordinated by carboxylate ligands. The interaction of the enzyme with the electron-accepting proteins cytochrome C556 and pseudoazurin is mainly hydrophobic. The catalytic mechanism of Hydroxylamine Oxidase from P. denitrificans is different from the enzyme from N. europaea because the production of nitrite by the former requires molecular oxygen. Under anaerobic conditions the enzyme makes nitrous oxide as a sole product.
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purification of Hydroxylamine Oxidase from thiosphaera pantotropha identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, D J RichardsonAbstract:Thiosphaera pantotropha, a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome c551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
Stephen Spiro - One of the best experts on this subject based on the ideXlab platform.
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MiCrObiology (1 997), 143, 3775-3783 Printed in Great Britain Heterologous expression of heterotrophic nitrification genes
2015Co-Authors: Lisa C. Crossman, Stephen Spiro, David J Richardson, James W B Moir, Julie T J. Enticknap, Of EastAbstract:Paracoccus denitrificans is a heterotrophic organism capable of oxidizing ammonia to nitrite during growth on an organic carbon and energy source. This pathway, termed heterotrophic nitrification, requires the concerted action of an ammonia monooxygenase (AMO) and Hydroxylamine Oxidase (HAO). The genes required for heterotrophic nitrification have been isolated by introducing a Pa. denitrificans genomic library into Pseudomonas putida and screening for the accumulation of nitrite. In contrast to the situation in chemolithoautotrophic ammonia oxidizers, the genes encoding AM0 and HA0 are present in single linked copies in the genome of Pa. denitrificans- AM0 from Pa. denitrificans expressed in Ps. putida is capable of oxidizing ethene (ethylene) to epoxyethane (ethylene oxide), which is indicative of a relaxed substrate specificity. Further, when expressed in the methylotroph Methylobacterium extorquens AMI, the AM0 endows on th is organism the ability to grow on ethene and methane. Thus, the Pa. denitrificans AM0 is capable of oxidizing methane t o methanol, as is the case for the AM0 from Nitrosomonas europaea. The heterotrophic nitrification genes are moderately toxic in M. extorquens, more toxic in Ps. putida, and non-toxic in Escherichia coli. Toxicity is due to the activity of the gene products in M. extorquens, and both expression and activity in Ps. putida. This is the first time that the genes encoding an active AM0 have been expressed in a heterologous host
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the biochemical characterization of a novel non haem iron Hydroxylamine Oxidase from paracoccus denitrificans gb17
Biochemical Journal, 1996Co-Authors: James W B Moir, Josa Marie Wehrfritz, Stephen Spiro, D J RichardsonAbstract:The characterization of the Hydroxylamine Oxidase from the heterotrophic nitrifier Paracoccus denitrificans GB17 indicates the enzyme to be entirely distinct from the Hydroxylamine Oxidase from the autotrophic nitrifier Nitrosomonas europaea. Hydroxylamine Oxidase from P. denitrificans contains three to five non-haem, non-iron-sulphur iron atoms as prosthetic groups, predominantly co-ordinated by carboxylate ligands. The interaction of the enzyme with the electron-accepting proteins cytochrome C556 and pseudoazurin is mainly hydrophobic. The catalytic mechanism of Hydroxylamine Oxidase from P. denitrificans is different from the enzyme from N. europaea because the production of nitrite by the former requires molecular oxygen. Under anaerobic conditions the enzyme makes nitrous oxide as a sole product.
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Purification of Hydroxylamine Oxidase from Thiosphaera pantotropha. Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification.
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, David J RichardsonAbstract:Abstract Thiosphaera pantotropha , a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C 551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
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purification of Hydroxylamine Oxidase from thiosphaera pantotropha identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, D J RichardsonAbstract:Thiosphaera pantotropha, a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome c551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
David J Richardson - One of the best experts on this subject based on the ideXlab platform.
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MiCrObiology (1 997), 143, 3775-3783 Printed in Great Britain Heterologous expression of heterotrophic nitrification genes
2015Co-Authors: Lisa C. Crossman, Stephen Spiro, David J Richardson, James W B Moir, Julie T J. Enticknap, Of EastAbstract:Paracoccus denitrificans is a heterotrophic organism capable of oxidizing ammonia to nitrite during growth on an organic carbon and energy source. This pathway, termed heterotrophic nitrification, requires the concerted action of an ammonia monooxygenase (AMO) and Hydroxylamine Oxidase (HAO). The genes required for heterotrophic nitrification have been isolated by introducing a Pa. denitrificans genomic library into Pseudomonas putida and screening for the accumulation of nitrite. In contrast to the situation in chemolithoautotrophic ammonia oxidizers, the genes encoding AM0 and HA0 are present in single linked copies in the genome of Pa. denitrificans- AM0 from Pa. denitrificans expressed in Ps. putida is capable of oxidizing ethene (ethylene) to epoxyethane (ethylene oxide), which is indicative of a relaxed substrate specificity. Further, when expressed in the methylotroph Methylobacterium extorquens AMI, the AM0 endows on th is organism the ability to grow on ethene and methane. Thus, the Pa. denitrificans AM0 is capable of oxidizing methane t o methanol, as is the case for the AM0 from Nitrosomonas europaea. The heterotrophic nitrification genes are moderately toxic in M. extorquens, more toxic in Ps. putida, and non-toxic in Escherichia coli. Toxicity is due to the activity of the gene products in M. extorquens, and both expression and activity in Ps. putida. This is the first time that the genes encoding an active AM0 have been expressed in a heterologous host
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Purification of Hydroxylamine Oxidase from Thiosphaera pantotropha. Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification.
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, David J RichardsonAbstract:Abstract Thiosphaera pantotropha , a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C 551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
Ann Reilly - One of the best experts on this subject based on the ideXlab platform.
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Purification of Hydroxylamine Oxidase from Thiosphaera pantotropha. Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification.
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, David J RichardsonAbstract:Abstract Thiosphaera pantotropha , a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C 551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
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purification of Hydroxylamine Oxidase from thiosphaera pantotropha identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification
FEBS Letters, 1993Co-Authors: Josa Marie Wehrfritz, Ann Reilly, Stephen Spiro, D J RichardsonAbstract:Thiosphaera pantotropha, a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic Hydroxylamine Oxidase that differs markedly from the Hydroxylamine Oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome c551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
