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Debabrata Sircar - One of the best experts on this subject based on the ideXlab platform.
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Benzoate-CoA ligase contributes to the biosynthesis of biphenyl phytoalexins in elicitor-treated pear cell cultures
Plant Cell Reports, 2020Co-Authors: Shashank Sagar Saini, Mariam Gaid, Debabrata SircarAbstract:Key message Benzoate-Coenzyme A ligase enzyme activity catalyzing the conversion of free benzoic acid to benzoyl-CoA was detected and biochemically characterized in the elicitor-treated pear cell cultures. Abstract Asian pear ( Pyrus pyrifolia ) is an economically and nutritionally important fruit-bearing tree of the subtribe Malinae. Upon pathogen attack, pears produce unique benzoate-derived biphenyl phytoalexins. The upstream biosynthesis of the biphenyl in Malinae is still incomplete. Previously, protein preparations from yeast extract-treated pear cultures were able to convert l -phenylalanine to cinnamic acid catalyzed by the activity of the phenylalanine ammonia lyase. The same extract was able to perform a C_2 side-chain cleavage of cinnamic acid to benzaldehyde followed by oxidation of the latter to benzoic acid owing to the molecularly-undefined benzaldehyde synthase and benzaldehyde dehydrogenase activities, respectively. The biosynthesis of Biphenyls starts with benzoate-Coenzyme A ligase (BZL), which converts benzoic acid to benzoyl-CoA. Subsequently, the previously-defined biphenyl synthase uses benzoyl-CoA to form the Biphenyls. The current study reports the first time detection and characterization of BZL activity in elicitor-treated pear cell cultures. The preferred substrate was benzoic acid ( K _m = 62 ± 4 µM). Magnesium or manganese was prerequisite for the activity, which was enhanced by ~ 70% in the presence of potassium. Maximum BZL activity was observed 18 h post elicitation, which is in agreement with the coordinate induction reported for the enzymes in the same pathway. The induced BZL activity preceded the accumulation of Biphenyls supporting its involvement in their biosynthesis.
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Benzoate-CoA ligase contributes to the biosynthesis of biphenyl phytoalexins in elicitor-treated pear cell cultures.
Plant Cell Reports, 2019Co-Authors: Shashank Sagar Saini, Mariam Gaid, Debabrata SircarAbstract:Benzoate-Coenzyme A ligase enzyme activity catalyzing the conversion of free benzoic acid to benzoyl-CoA was detected and biochemically characterized in the elicitor-treated pear cell cultures. Asian pear (Pyrus pyrifolia) is an economically and nutritionally important fruit-bearing tree of the subtribe Malinae. Upon pathogen attack, pears produce unique benzoate-derived biphenyl phytoalexins. The upstream biosynthesis of the biphenyl in Malinae is still incomplete. Previously, protein preparations from yeast extract-treated pear cultures were able to convert l-phenylalanine to cinnamic acid catalyzed by the activity of the phenylalanine ammonia lyase. The same extract was able to perform a C2 side-chain cleavage of cinnamic acid to benzaldehyde followed by oxidation of the latter to benzoic acid owing to the molecularly-undefined benzaldehyde synthase and benzaldehyde dehydrogenase activities, respectively. The biosynthesis of Biphenyls starts with benzoate-Coenzyme A ligase (BZL), which converts benzoic acid to benzoyl-CoA. Subsequently, the previously-defined biphenyl synthase uses benzoyl-CoA to form the Biphenyls. The current study reports the first time detection and characterization of BZL activity in elicitor-treated pear cell cultures. The preferred substrate was benzoic acid (Km = 62 ± 4 µM). Magnesium or manganese was prerequisite for the activity, which was enhanced by ~ 70% in the presence of potassium. Maximum BZL activity was observed 18 h post elicitation, which is in agreement with the coordinate induction reported for the enzymes in the same pathway. The induced BZL activity preceded the accumulation of Biphenyls supporting its involvement in their biosynthesis.
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Molecular cloning and functional analysis of a biphenyl phytoalexin-specific O-methyltransferase from apple cell suspension cultures
Planta, 2019Co-Authors: Amol Sarkate, Ludger Beerhues, Shashank Sagar Saini, Mariam Gaid, Deepa Teotia, Javid Iqbal Mir, Pawan Kumar Agrawal, Debabrata SircarAbstract:Main conclusion This manuscript describes the cloning and functional characterization of a biphenyl phytoalexin biosynthetic gene, 3,5 - dihydroxybiphenyl O - methyltransferase from elicitor-treated cell cultures of scab resistant apple cultivar ‘Florina’. Apples belong to the subtribe Malinae of the Rosaceae family. Biphenyls and dibenzofurans are the specialized phytoalexins of Malinae, of which aucuparin is the most widely distributed biphenyl. The precursor of aucuparin, 3,5-dihydroxybiphenyl, is a benzoate-derived polyketide, which is formed by the sequential condensation of three molecules of malonyl-CoA and one molecule of benzoyl-CoA in a reaction catalyzed by biphenyl synthase (BIS). This 3,5-dihydroxybiphenyl then undergoes sequential 5- O -methylation, 4-hydroxylation, and finally 3- O -methylation to form aucuparin. A cDNA encoding O -methyltransferase (OMT) was isolated and functionally characterized from the cell cultures of scab-resistant apple cultivar ‘Florina’ ( Malus domestica cultivar ‘Florina’; MdOMT) after treatment with elicitor prepared from the apple scab causing fungus Venturia inaequalis. MdOMT catalyzed the regiospecific O -methylation of 3,5-dihydroxybiphenyl at the 5-position to form 3-hydroxy-5-methoxybiphenyl. The enzyme showed absolute substrate preference for 3,5-dihydroxybiphenyl. The elicitor-treated apple cell cultures showed transient increases in the MdOMT (GenBank ID MF740747) and MdBIS3 (GenBank ID JQ390523) transcript levels followed by the accumulation of Biphenyls (aucuparin and noraucuparin) and dibenzofuran (eriobofuran) phytoalexins. MdOMT fused with N- and C -terminal yellow fluorescent protein showed cytoplasmic localization in the epidermis of Nicotiana benthamiana leaves. In scab inoculated greenhouse-grown ‘Florina’ plants, the expression of MdOMT was transiently induced in the stem followed by the accumulation of biphenyl phytoalexins.
Shashank Sagar Saini - One of the best experts on this subject based on the ideXlab platform.
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Benzoate-CoA ligase contributes to the biosynthesis of biphenyl phytoalexins in elicitor-treated pear cell cultures
Plant Cell Reports, 2020Co-Authors: Shashank Sagar Saini, Mariam Gaid, Debabrata SircarAbstract:Key message Benzoate-Coenzyme A ligase enzyme activity catalyzing the conversion of free benzoic acid to benzoyl-CoA was detected and biochemically characterized in the elicitor-treated pear cell cultures. Abstract Asian pear ( Pyrus pyrifolia ) is an economically and nutritionally important fruit-bearing tree of the subtribe Malinae. Upon pathogen attack, pears produce unique benzoate-derived biphenyl phytoalexins. The upstream biosynthesis of the biphenyl in Malinae is still incomplete. Previously, protein preparations from yeast extract-treated pear cultures were able to convert l -phenylalanine to cinnamic acid catalyzed by the activity of the phenylalanine ammonia lyase. The same extract was able to perform a C_2 side-chain cleavage of cinnamic acid to benzaldehyde followed by oxidation of the latter to benzoic acid owing to the molecularly-undefined benzaldehyde synthase and benzaldehyde dehydrogenase activities, respectively. The biosynthesis of Biphenyls starts with benzoate-Coenzyme A ligase (BZL), which converts benzoic acid to benzoyl-CoA. Subsequently, the previously-defined biphenyl synthase uses benzoyl-CoA to form the Biphenyls. The current study reports the first time detection and characterization of BZL activity in elicitor-treated pear cell cultures. The preferred substrate was benzoic acid ( K _m = 62 ± 4 µM). Magnesium or manganese was prerequisite for the activity, which was enhanced by ~ 70% in the presence of potassium. Maximum BZL activity was observed 18 h post elicitation, which is in agreement with the coordinate induction reported for the enzymes in the same pathway. The induced BZL activity preceded the accumulation of Biphenyls supporting its involvement in their biosynthesis.
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Benzoate-CoA ligase contributes to the biosynthesis of biphenyl phytoalexins in elicitor-treated pear cell cultures.
Plant Cell Reports, 2019Co-Authors: Shashank Sagar Saini, Mariam Gaid, Debabrata SircarAbstract:Benzoate-Coenzyme A ligase enzyme activity catalyzing the conversion of free benzoic acid to benzoyl-CoA was detected and biochemically characterized in the elicitor-treated pear cell cultures. Asian pear (Pyrus pyrifolia) is an economically and nutritionally important fruit-bearing tree of the subtribe Malinae. Upon pathogen attack, pears produce unique benzoate-derived biphenyl phytoalexins. The upstream biosynthesis of the biphenyl in Malinae is still incomplete. Previously, protein preparations from yeast extract-treated pear cultures were able to convert l-phenylalanine to cinnamic acid catalyzed by the activity of the phenylalanine ammonia lyase. The same extract was able to perform a C2 side-chain cleavage of cinnamic acid to benzaldehyde followed by oxidation of the latter to benzoic acid owing to the molecularly-undefined benzaldehyde synthase and benzaldehyde dehydrogenase activities, respectively. The biosynthesis of Biphenyls starts with benzoate-Coenzyme A ligase (BZL), which converts benzoic acid to benzoyl-CoA. Subsequently, the previously-defined biphenyl synthase uses benzoyl-CoA to form the Biphenyls. The current study reports the first time detection and characterization of BZL activity in elicitor-treated pear cell cultures. The preferred substrate was benzoic acid (Km = 62 ± 4 µM). Magnesium or manganese was prerequisite for the activity, which was enhanced by ~ 70% in the presence of potassium. Maximum BZL activity was observed 18 h post elicitation, which is in agreement with the coordinate induction reported for the enzymes in the same pathway. The induced BZL activity preceded the accumulation of Biphenyls supporting its involvement in their biosynthesis.
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Molecular cloning and functional analysis of a biphenyl phytoalexin-specific O-methyltransferase from apple cell suspension cultures
Planta, 2019Co-Authors: Amol Sarkate, Ludger Beerhues, Shashank Sagar Saini, Mariam Gaid, Deepa Teotia, Javid Iqbal Mir, Pawan Kumar Agrawal, Debabrata SircarAbstract:Main conclusion This manuscript describes the cloning and functional characterization of a biphenyl phytoalexin biosynthetic gene, 3,5 - dihydroxybiphenyl O - methyltransferase from elicitor-treated cell cultures of scab resistant apple cultivar ‘Florina’. Apples belong to the subtribe Malinae of the Rosaceae family. Biphenyls and dibenzofurans are the specialized phytoalexins of Malinae, of which aucuparin is the most widely distributed biphenyl. The precursor of aucuparin, 3,5-dihydroxybiphenyl, is a benzoate-derived polyketide, which is formed by the sequential condensation of three molecules of malonyl-CoA and one molecule of benzoyl-CoA in a reaction catalyzed by biphenyl synthase (BIS). This 3,5-dihydroxybiphenyl then undergoes sequential 5- O -methylation, 4-hydroxylation, and finally 3- O -methylation to form aucuparin. A cDNA encoding O -methyltransferase (OMT) was isolated and functionally characterized from the cell cultures of scab-resistant apple cultivar ‘Florina’ ( Malus domestica cultivar ‘Florina’; MdOMT) after treatment with elicitor prepared from the apple scab causing fungus Venturia inaequalis. MdOMT catalyzed the regiospecific O -methylation of 3,5-dihydroxybiphenyl at the 5-position to form 3-hydroxy-5-methoxybiphenyl. The enzyme showed absolute substrate preference for 3,5-dihydroxybiphenyl. The elicitor-treated apple cell cultures showed transient increases in the MdOMT (GenBank ID MF740747) and MdBIS3 (GenBank ID JQ390523) transcript levels followed by the accumulation of Biphenyls (aucuparin and noraucuparin) and dibenzofuran (eriobofuran) phytoalexins. MdOMT fused with N- and C -terminal yellow fluorescent protein showed cytoplasmic localization in the epidermis of Nicotiana benthamiana leaves. In scab inoculated greenhouse-grown ‘Florina’ plants, the expression of MdOMT was transiently induced in the stem followed by the accumulation of biphenyl phytoalexins.
Mohamed S. Nawaz - One of the best experts on this subject based on the ideXlab platform.
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Degradation of acetonitrile and biphenyl compounds by a mixed microbial culture
Environmental Toxicology and Chemistry, 1992Co-Authors: Kirit D. Chapatwala, G. R. V. Babu, Mohamed S. NawazAbstract:A mixed microbial culture was isolated from an environment contaminated with organic cyanides and polychlorinated Biphenyls (PCBs). This mixed culture could utilize acetonitrile as the sole source of carbon and nitrogen, and biphenyl as the sole source of carbon. This mixed culture also utilized nitriles, their respective amides, and several PCBs as growth substrates. Studies involving the radiolabeled compounds indicated that nearly 70% of [14C]acetonitrile and 51% of [14C]biphenyl were recovered as 14CO2. The end products resulted during the degradation of acetonitrile and biphenyl were identified as ammonia and benzoate, respectively. It was also observed that the mixed culture that can degrade biphenyl loses its capability when transferred repeatedly into a medium supplemented with acetonitrile as growth substrate. The present study suggests that the application of mixed rather than pure microbial culture is more effective in bioremediation of toxic chemicals.
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Simultaneous degradation of acetonitrile and biphenyl by Pseudomonas aeruginosa.
Canadian journal of microbiology, 1991Co-Authors: Mohamed S. Nawaz, Kirit D. ChapatwalaAbstract:A bacterium capable of utilizing either acetonitrile as the sole source of carbon and nitrogen or biphenyl as the sole source of carbon was isolated from soil and identified as Pseudomonas aeruginosa. The bacterium also utilized other nitriles, amides, and polychlorinated Biphenyls (PCBs) as growth substrates. Acetonitrile- or biphenyl-grown cells oxidized these substrates without a lag. In studies with [14C]acetonitrile, nearly 74% of the carbon was recovered as 14CO2 and 8% was associated with the biomass. In studies with [14C]biphenyl, nearly 68% of the carbon was recovered as 14CO2 and nearly 6% was associated with the biomass. Although higher concentrations of acetonitrile as the sole sources of nitrogen inhibited the rates of [14C]biphenyl mineralization, lower concentrations (0.05%, w/v) gave a 77% stimulation in 14CO2 recovery. Pseudomonas aeruginosa metabolized acetonitrile to ammonia and acetic acid and biphenyl to benzoic acid. The bacterium also simultaneously utilized biphenyl as the sole car...
David T. Gibson - One of the best experts on this subject based on the ideXlab platform.
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DIHYDROXYLATION AND DECHLORINATION OF CHLORINATED Biphenyls BY PURIFIED BIPHENYL 2,3-DIOXYGENASE FROM PSEUDOMONAS SP. STRAIN LB400
Journal of bacteriology, 1995Co-Authors: J D Haddock, J R Horton, David T. GibsonAbstract:Oxidation of biphenyl and nine chlorinated Biphenyls (CBs) by the biphenyl 2,3-dioxygenase from Pseudomonas sp. strain LB400 was examined. The purified terminal oxygenase required the addition of partially purified electron transport components, NAD(P)H, and ferrous iron to oxidize biphenyl and CBs. cis-Biphenyl 2,3-dihydrodiol was produced with biphenyl as the substrate. Dihydrodiols were produced from all CBs, and more than one compound was produced with most substrates. Catechols were produced when the dioxygenase-catalyzed reaction occurred at the 2,3 position of a 2-chlorophenyl ring, resulting in dechlorination of the substrate. Oxidation at the 3,4 position of a 2,5-dichlorophenyl ring produced a 3,4-dihydrodiol. Compounds resulting from both types of reaction were produced during oxidation of 2,5,2'-trichlorobiphenyl. The broad substrate specificity and the ability to oxidize at different ring positions suggest that the biphenyl 2,3-dioxygenase is responsible for the wide range of CBs oxidized by Pseudomonas sp. strain LB400.
Kensuke Furukawa - One of the best experts on this subject based on the ideXlab platform.
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Draft Genome Sequence of Pseudomonas toyotomiensis KF710, a Polychlorinated Biphenyl-Degrading Bacterium Isolated from Biphenyl-Contaminated Soil
Genome announcements, 2015Co-Authors: Takahito Watanabe, Atsushi Yamazoe, Akira Hosoyama, Hidehiko Fujihara, Hikaru Suenaga, Jun Hirose, Taiki Futagami, Masatoshi Goto, Nobutada Kimura, Kensuke FurukawaAbstract:ABSTRACT Pseudomonas toyotomiensis KF710 utilizes biphenyl and degrades polychlorinated Biphenyls (PCBs). Here, we report the genome sequence of the KF710 strain, consisting of 5,596,721 bp with 5,155 coding sequences. The biphenyl catabolic genes were almost identical to those of Pseudomonas pseudoalcaligenes KF707, one of the most well-characterized biphenyl-utilizing strains.
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enhanced degradation of polychlorinated Biphenyls by directed evolution of biphenyl dioxygenase
Nature Biotechnology, 1998Co-Authors: Tetsuya Kumamaru, Takahito Watanabe, Hikaru Suenaga, Mariko Mitsuoka, Kensuke FurukawaAbstract:Biphenyl dioxygenases (BP Dox) from different organisms, which are involved in the initial oxygenation and subsequent degradation of polychlorinated Biphenyls (PCB), are similar in structure but have different functions. The large subunit of BP Dox, encoded by the bphA1 gene, is crucial for substrate selectivity. Using the process of DMA shuffling, we randomly recombined the bphA1 genes of Pseudomonas pseudoalcaligenes KF707 and Burkholderia cepacia LB400 and selected for genes that expressed proteins with altered function. Upon expression in Escherichia coli, some of these evolved genes exhibited enhanced degradation capacity, not only for PCB and related biphenyl compounds, but for single aromatic hydrocarbons such as benzene and toluene, which are poor substrates for the original BP Dox.
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analysis of bph operon from the polychlorinated biphenyl degrading strain of pseudomonas pseudoalcaligenes kf707
Journal of Biological Chemistry, 1992Co-Authors: K Taira, Jun Hirose, Shinsaku Hayashida, Kensuke FurukawaAbstract:Abstract The entire nucleotide sequences (6.8 kilobase pairs) of the bphABC genes and their products involved in the initial dioxygenation and ring-meta-cleavage of Biphenyls and polychlorinated Biphenyls were determined. The first bphA gene starts about a 100 base pairs downstream from the transcriptional initiation site. The bphA region, which encodes a cluster of enzymes including biphenyl dioxygenase catalyzing the initial catabolic step, consists of five open reading frames (ORFs). Five proteins corresponding to these ORFs in the molecular masses were detected by in vitro protein synthesis, of which four ORFs are very similar to the recently reported todC1C2BA genes coding for the corresponding enzymes catalyzing the initial dioxygenation reactions of toluene (Zylstra, G.J., and Gibson, D. T. (1989) J. Biol. Chem. 264, 14940-14946). The third open reading frame (ORF3) of the bphA region, missing its counterpart in the toluene dioxygenase gene cluster, was site-specifically deleted, and the resulting enzymatically active mutant reveals that this ORF3 is not mandatory for the catabolism of Biphenyls. Thus the biphenyl degradation pathway and the responsible enzymes/genes are very similar to those of toluene degradation despite their discrete substrate specificity.