Discovery and Biocatalytic Application of a PLP-Dependent Amino Acid γ-Substitution Enzyme that Catalyzes C-C Bond Formation

2020 ◽  
Author(s):  
Mengbin Chen ◽  
Chun-Ting Liu ◽  
Yi Tang
Keyword(s):  
Amino Acids ◽  
Biosynthetic Pathway ◽  
Pyridoxal Phosphate ◽  
Biochemical Characterization ◽  
Indole Alkaloid ◽  
Building Blocks ◽  
Nucleophilic Attack ◽  
Keto Esters ◽  
Key Enzyme

Pyridoxal phosphate (PLP)-dependent enzymes can catalyze various transformations of amino acids at alpha, beta, and gamma positions. These versatile enzymes are prominently involved in the biosynthesis of nonproteinogenic amino acids as building blocks of natural products, and are attractive biocatalysts. Here, we report the discovery of a two-step enzymatic synthesis of (2<i>S, </i>6<i>S</i>)-6-methyl pipecolate <b>1</b>, from the biosynthetic pathway of indole alkaloid citrinadin. The key enzyme CndF is PLP-dependent and catalyzes synthesis of (<i>S</i>)-2-amino-6-oxoheptanoate <b>3</b> that is in equilibrium with the cyclic Schiff base. The second enzyme CndE is a stereoselective imine reductase that gives <b>1</b>. Biochemical characterization of CndF showed this enzyme performs gamma-elimination of <i>O</i>-acetyl L-homoserine to generate the vinylglycine ketimine, which is subjected to nucleophilic attack by acetoacetate to form the new C<sub>gamma</sub>-C<sub>delta</sub> bond in <b>3 </b>and complete the gamma-substitution reaction. CndF displays substrate promiscuity towards different beta-keto carboxylate and esters. Using a recombinant <i>Aspergillus </i>strain expressing CndF and CndE, feeding various alkyl-beta-keto esters led to the biosynthesis of 6-substituted L-pipecolates. The discovery of CndF expands the repertoire of reactions that can be catalyzed by PLP-dependent enzymes.

Discovery and Biocatalytic Application of a PLP-Dependent Amino Acid γ-Substitution Enzyme that Catalyzes C-C Bond Formation

2020 ◽  
Author(s):  
Mengbin Chen ◽  
Chun-Ting Liu ◽  
Yi Tang
Keyword(s):  
Amino Acids ◽  
Biosynthetic Pathway ◽  
Pyridoxal Phosphate ◽  
Biochemical Characterization ◽  
Indole Alkaloid ◽  
Building Blocks ◽  
Nucleophilic Attack ◽  
Keto Esters ◽  
Key Enzyme

Pyridoxal phosphate (PLP)-dependent enzymes can catalyze various transformations of amino acids at alpha, beta, and gamma positions. These versatile enzymes are prominently involved in the biosynthesis of nonproteinogenic amino acids as building blocks of natural products, and are attractive biocatalysts. Here, we report the discovery of a two-step enzymatic synthesis of (2<i>S, </i>6<i>S</i>)-6-methyl pipecolate <b>1</b>, from the biosynthetic pathway of indole alkaloid citrinadin. The key enzyme CndF is PLP-dependent and catalyzes synthesis of (<i>S</i>)-2-amino-6-oxoheptanoate <b>3</b> that is in equilibrium with the cyclic Schiff base. The second enzyme CndE is a stereoselective imine reductase that gives <b>1</b>. Biochemical characterization of CndF showed this enzyme performs gamma-elimination of <i>O</i>-acetyl L-homoserine to generate the vinylglycine ketimine, which is subjected to nucleophilic attack by acetoacetate to form the new C<sub>gamma</sub>-C<sub>delta</sub> bond in <b>3 </b>and complete the gamma-substitution reaction. CndF displays substrate promiscuity towards different beta-keto carboxylate and esters. Using a recombinant <i>Aspergillus </i>strain expressing CndF and CndE, feeding various alkyl-beta-keto esters led to the biosynthesis of 6-substituted L-pipecolates. The discovery of CndF expands the repertoire of reactions that can be catalyzed by PLP-dependent enzymes.

scholarly journals Structural and Biochemical Characterization of the Salicylyl-acyltranferase SsfX3 from a Tetracycline Biosynthetic Pathway

2011 ◽  
Vol 286 (48) ◽  
pp. 41539-41551 ◽  
Author(s):  
Lauren B. Pickens ◽  
Michael R. Sawaya ◽  
Huma Rasool ◽  
Inna Pashkov ◽  
Todd O. Yeates ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Biochemical Characterization

scholarly journals Phenotypic, Genetic and Biochemical Characterization of Five Tunisian Varieties of Chickpea

2017 ◽  
Vol 5 (1) ◽  
pp. 77 ◽  
Author(s):  
Mongi Melki ◽  
Abir Gsouri ◽  
Mariem Bouhadida ◽  
Hnya Chograni ◽  
Mohsen Rezgui
Keyword(s):  
Amino Acids ◽  
Biochemical Characterization ◽  
Block Design ◽  
Field Trials ◽  
Morphological Characters ◽  
Yield Potential ◽  
Polymorphism Analysis ◽  
Sulfur Amino Acids ◽  
Semi Arid Region

Five Tunisian varieties of Kabuli chickpea were characterized based on agro morphological, molecular and biochemical parameters to investigate their genetic variability and yield potential. Randomized complete block design field trials were carried out in the upper semi-arid region of Kef in Tunisia during the 2013-2014 seasons. Data analysis showed significant differences between genotypes for several parameters. The results indicated that these genotypes could be set into two different groups. The first group composed of Bochra and Chetoui genotypes. Kasseb, Neyer and Beja1 were in the second group. Genotypes in each group were closely related to each other according to their common morphological characters such as pod number, one hundred seeds weight and yield.  Chetoui and Kasseb varieties are later in comparison to other varieties. Genetic diversity was studied using simple sequence repeat (SSR) markers. Four loci (TA64, TA71, TA96, TA194) were multiallelic. Whereas while two loci (TA72, GAA47) were monomorphic. Polymorphism analysis showed a phylogeny related to genotypes differentiation according to their relatives, origin and several morphological characters. Bochra variety had high amino acids content followed by Chetoui variety. All the varieties were deficient in sulfur amino acids. Chickpeas protein contents were variable and high ranging from 18% to 25%.

scholarly journals Biochemical Characterization of the CDP-D-Arabinitol Biosynthetic Pathway in Streptococcus pneumoniae 17F

2012 ◽  
Vol 194 (8) ◽  
pp. 1868-1874 ◽  
Author(s):  
Q. Wang ◽  
Y. Xu ◽  
A. V. Perepelov ◽  
Y. A. Knirel ◽  
P. R. Reeves ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Biosynthetic Pathway ◽  
Biochemical Characterization

Biochemical Characterization of Branched Chain Amino Acids Uptake in Trypanosoma cruzi

2015 ◽  
Vol 63 (3) ◽  
pp. 299-308 ◽  
Author(s):  
Nubia C. Manchola ◽  
Ludmila N. Rapado ◽  
María J. Barisón ◽  
Ariel M. Silber
Keyword(s):  
Amino Acids ◽  
Trypanosoma Cruzi ◽  
Biochemical Characterization ◽  
Branched Chain Amino Acids ◽  
Branched Chain

Growth and biochemical characterization of associations between cyanobionts and wheat seedlings in co-culturing experiments

Biologia ◽  
2011 ◽  
Vol 66 (1) ◽  
Author(s):  
Anjuli Sood ◽  
Pawan Singh ◽  
Arun Kumar ◽  
Rajendra Singh ◽  
Radha Prasanna
Keyword(s):  
Amino Acids ◽  
Indoleacetic Acid ◽  
Biochemical Characterization ◽  
Shoot Biomass ◽  
Wheat Seedlings ◽  
Symbiotic Associations ◽  
Plant Groups ◽  
Wide Range ◽  
Root And Shoot Biomass

AbstractN2-fixing cyanobacteria are unique in their capacity to form symbiotic associations with a wide range of eukaryotic hosts belonging to different plant groups. The present study was undertaken to analyze the interactions of the cyanobiont PI 01 (from Azolla pinnata) and Nostoc PCC 9229 (from Gunnera monoika) with wheat seedlings, in co-culturing experiments. Each of the cyanobionts enhanced significantly the volume of root and shoot biomass in the experimental cultures. The transverse sections of roots in the co-cultured seedlings revealed the presence of aseriate packets of cyanobionts below the root epidermis. The investigated cyanobionts excreted amino acids (His, Met, Val) and sugars into the medium, while indoleacetic acid was detected when the cyanobionts were grown in a tryptophan containing medium. During the co-culturing, sugars and proline were detected in the extracellular filtrates. It can be hypothesized that these sugars and amino acids may serve as signal substances in the development of functional associations between the relevant cyanobionts and the wheat seedlings.

scholarly journals Genetic and Biochemical Characterization of OXA-535, a Distantly Related OXA-48-Like β-Lactamase

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
L. Dabos ◽  
A. B. Jousset ◽  
R. A. Bonnin ◽  
N. Fortineau ◽  
A. Zavala ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequence Identity ◽  
Biochemical Characterization ◽  
Content Type ◽  
Sequence Identity

ABSTRACT OXA-535 is a chromosome-encoded carbapenemase of Shewanella bicestrii JAB-1 that shares only 91.3% amino acid sequence identity with OXA-48. Catalytic efficiencies are similar to those of OXA-48 for most β-lactams, except for ertapenem, where a 2,000-fold-higher efficiency was observed with OXA-535. OXA-535 and OXA-436, a plasmid-encoded variant of OXA-535 differing by three amino acids, form a novel cluster of distantly related OXA-48-like carbapenemases. Comparison of blaOXA-535 and blaOXA-436 genetic environments suggests that an ISCR1 may be responsible for blaOXA-436 gene mobilization from the chromosome of Shewanella spp. to plasmids.

scholarly journals Characterization of an Escherichia coli K12 mutant that is sensitive to chlorate when grown aerobically

1978 ◽  
Vol 176 (2) ◽  
pp. 553-561 ◽  
Author(s):  
G Giordano ◽  
L Grillet ◽  
R Rosset ◽  
J H Dou ◽  
E Azoulay ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biosynthetic Pathway ◽  
Formate Dehydrogenase ◽  
Biochemical Characterization ◽  
Reductase Activity ◽  
Growth Conditions ◽  
Aerobic Growth ◽  
Benzyl Viologen ◽  
Genetic Lesion

Escherichia coli can normally grow aerobically in the presence of chlorate; however, mutants can be isolated that can no longer grow under these conditions. We present here the biochemical characterization of one such mutant and show that the primary genetic lesion occurs in the ubiquinone-8-biosynthetic pathway. As a consequence of this, under aerobic growth conditions the mutant is apparently unable to synthesize formate dehydrogenase, but can synthesize a Benzyl Viologen-dependent nitrate reductase activity. The nature of this activity is discussed.

scholarly journals Purification, Overproduction, and Partial Characterization of β-RFAP Synthase, a Key Enzyme in the Methanopterin Biosynthesis Pathway†

2002 ◽  
Vol 184 (16) ◽  
pp. 4442-4448 ◽  
Author(s):  
Joseph W. Scott ◽  
Madeline E. Rasche
Keyword(s):  
Biosynthetic Pathway ◽  
Methanogenic Archaea ◽  
Methylotrophic Bacteria ◽  
Methylobacterium Extorquens ◽  
Gene Encoding ◽  
Methanosarcina Thermophila ◽  
Inorganic Pyrophosphate ◽  
Sulfate Reducing ◽  
Key Enzyme

ABSTRACT Methanopterin is a folate analog involved in the C1 metabolism of methanogenic archaea, sulfate-reducing archaea, and methylotrophic bacteria. Although a pathway for methanopterin biosynthesis has been described in methanogens, little is known about the enzymes and genes involved in the biosynthetic pathway. The enzyme β-ribofuranosylaminobenzene 5′-phosphate synthase (β-RFAP synthase) catalyzes the first unique step to be identified in the pathway of methanopterin biosynthesis, namely, the condensation of p-aminobenzoic acid with phosphoribosylpyrophosphate to form β-RFAP, CO2, and inorganic pyrophosphate. The enzyme catalyzing this reaction has not been purified to homogeneity, and the gene encoding β-RFAP synthase has not yet been identified. In the present work, we report on the purification to homogeneity of β-RFAP synthase. The enzyme was purified from the methane-producing archaeon Methanosarcina thermophila, and the N-terminal sequence of the protein was used to identify corresponding genes from several archaea, including the methanogen Methanococcus jannaschii and the sulfate-reducing archaeon Archaeoglobus fulgidus. The putative β-RFAP synthase gene from A. fulgidus was expressed in Escherichia coli, and the enzymatic activity of the recombinant gene product was verified. A BLAST search using the deduced amino acid sequence of the β-RFAP synthase gene identified homologs in additional archaea and in a gene cluster required for C1 metabolism by the bacterium Methylobacterium extorquens. The identification of a gene encoding a potential β-RFAP synthase in M. extorquens is the first report of a putative methanopterin biosynthetic gene found in the Bacteria and provides evidence that the pathways of methanopterin biosynthesis in Bacteria and Archaea are similar.

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