Publications

• Cloning and expression of the limonene hydroxylase of Bacillus stearothermophilus BR388 and utilization in two-phase limonene conversions.

  Cheong T.K., Oriel P.J.

  A 3.6-kb fragment of Bacillus stearothermophilus BR388 chromosomal DNA that confers growth on limonene to Escherichia coli has been sequenced, revealing a single open reading frame encoding a single subunit limonene hydroxylase containing 444 amino acid residues. This enzyme proved capable of limo ... >> More

  A 3.6-kb fragment of Bacillus stearothermophilus BR388 chromosomal DNA that confers growth on limonene to Escherichia coli has been sequenced, revealing a single open reading frame encoding a single subunit limonene hydroxylase containing 444 amino acid residues. This enzyme proved capable of limonene hydroxylation to a mixture of carveol and perillyl alcohol as well as dehydrogenation of these products to carvone and perillyl aldehyde. Oxygen, FAD, and NADH were found to stimulate the hydroxylation reaction in cell extracts, and NAD+ stimulated the dehydrogenase reaction. In two-phase bioconversions using viable E. coli cells over-expressing the limonene hydroxylase, perillyl alcohol and carvone were the principal products observed. << Less

  Appl. Biochem. Biotechnol. 84:903-915(2000) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Geraniol and geranial dehydrogenases induced in anaerobic monoterpene degradation by Castellaniella defragrans.

  Luddeke F., Wulfing A., Timke M., Germer F., Weber J., Dikfidan A., Rahnfeld T., Linder D., Meyerdierks A., Harder J.

  Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed th ... >> More

  Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding open reading frame (ORF), the first bacterial gene for a GeDH (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase is a homodimeric enzyme that affiliates with the zinc-containing benzyl alcohol dehydrogenases in the superfamily of medium-chain-length dehydrogenases/reductases (MDR). The purified enzyme most efficiently catalyzes the oxidation of perillyl alcohol (k(cat)/K(m) = 2.02 × 10(6) M(-1) s(-1)), followed by geraniol (k(cat)/K(m) = 1.57 × 10(6) M(-1) s(-1)). Apparent K(m) values of <10 μM are consistent with an in vivo toxicity of geraniol above 5 μM. In the genetic vicinity of geoA is a putative aldehyde dehydrogenase that was named geoB and identified as a highly abundant protein during growth with phellandrene. Extracts of Escherichia coli expressing geoB demonstrated in vitro a geranial dehydrogenase (GaDH) activity. GaDH activity was independent of coenzyme A. The irreversible formation of geranic acid allows for a metabolic flux from β-myrcene via linalool, geraniol, and geranial to geranic acid. << Less

  Appl. Environ. Microbiol. 78:2128-2136(2012) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Detection and characterization of the lignin peroxidase compound II-veratryl alcohol cation radical complex.

  Khindaria A., Nie G., Aust S.D.

  Lignin peroxidases (LiP) from the white-rot fungus Phanerochaete chrysosporium oxidize veratryl alcohol (VA) by two electrons to veratryl aldehyde, although the VA cation radical (VA.+) is an intermediate [Khindaria, A., et al. (1995) Biochemistry 34, 6020-6025]. It was speculated, on the basis of ... >> More

  Lignin peroxidases (LiP) from the white-rot fungus Phanerochaete chrysosporium oxidize veratryl alcohol (VA) by two electrons to veratryl aldehyde, although the VA cation radical (VA.+) is an intermediate [Khindaria, A., et al. (1995) Biochemistry 34, 6020-6025]. It was speculated, on the basis of kinetic evidence, that VA*+ can form a catalytic complex with LiP compound II. We have used low-temperature EPR to provide direct evidence for the formation of the complex. The EPR spectrum of VA*+ obtained at 4 K was explained by a model for coupling between the oxoferryl moiety of the heme (S = 1) and VA.+ (S = 1/2) similar to the model proposed for an oxyferryl and a porphyrin pi cation radical of horseradish peroxidase. The coupling constant suggested that VA.+ was equally ferro- and antiferromagnetically coupled to the oxoferryl moiety. The spectrum was simulated with g perpendicular only marginally greater than g parallel. This was surprising since the only other known organic radical coupled to the heme iron in a peroxidase is the tryptophan cation radical in cytochrome c peroxidase which exhibits a g tensor with g parallel greater than g perpendicular. Spin concentration analysis suggested that the 1 mol of VA*+ was coupled to the oxoferryl moiety per mole of enzyme. The VA.+ signal decayed with a first-order decay constant of 1.76 s-1, in close agreement with the earlier published decay constant of 1.85 s-1 from room-temperature EPR studies. The exchange coupling between VA.+ and the oxoferryl moiety strongly advocates calling this species (VA.+ and LiP compound II) a catalytic complex. << Less

  Biochemistry 36:14181-14185(1997) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Coexpression analysis identifies two oxidoreductases involved in the biosynthesis of the monoterpene acid moiety of natural pyrethrin insecticides in Tanacetum cinerariifolium.

  Xu H., Moghe G.D., Wiegert-Rininger K., Schilmiller A.L., Barry C.S., Last R.L., Pichersky E.

  Flowers of <i>Tanacetum cinerariifolium</i> produce a set of compounds known collectively as pyrethrins, which are commercially important pesticides that are strongly toxic to flying insects but not to most vertebrates. A pyrethrin molecule is an ester consisting of either trans-chrysanthemic acid ... >> More

  Flowers of <i>Tanacetum cinerariifolium</i> produce a set of compounds known collectively as pyrethrins, which are commercially important pesticides that are strongly toxic to flying insects but not to most vertebrates. A pyrethrin molecule is an ester consisting of either trans-chrysanthemic acid or its modified form, pyrethric acid, and one of three alcohols, jasmolone, pyrethrolone, and cinerolone, that appear to be derived from jasmonic acid. Chrysanthemyl diphosphate synthase (CDS), the first enzyme involved in the synthesis of trans-chrysanthemic acid, was characterized previously and its gene isolated. <i>TcCDS</i> produces free trans-chrysanthemol in addition to trans-chrysanthemyl diphosphate, but the enzymes responsible for the conversion of trans-chrysanthemol to the corresponding aldehyde and then to the acid have not been reported. We used an RNA sequencing-based approach and coexpression correlation analysis to identify several candidate genes encoding putative trans-chrysanthemol and trans-chrysanthemal dehydrogenases. We functionally characterized the proteins encoded by these genes using a combination of in vitro biochemical assays and heterologous expression in planta to demonstrate that <i>TcADH2</i> encodes an enzyme that oxidizes trans-chrysanthemol to trans-chrysanthemal, while <i>TcALDH1</i> encodes an enzyme that oxidizes trans-chrysanthemal into trans-chrysanthemic acid. Transient coexpression of <i>TcADH2</i> and <i>TcALDH1</i> together with <i>TcCDS</i> in <i>Nicotiana benthamiana</i> leaves results in the production of trans-chrysanthemic acid as well as several other side products. The majority (58%) of trans-chrysanthemic acid was glycosylated or otherwise modified. Overall, these data identify key steps in the biosynthesis of pyrethrins and demonstrate the feasibility of metabolic engineering to produce components of these defense compounds in a heterologous host. << Less

  Plant Physiol. 176:524-537(2018) [PubMed] [EuropePMC]

  This publication is cited by 15 other entries.