A5003137941- Nitrogen and Sulfur Effects on Brassica
- Photosynthetic Processes and Mechanisms
- Plant Gene Expression Analysis
- Legume Nitrogen Fixing Symbiosis
- Phytase and its Applications
- Genomics, phytochemicals, and oxidative stress
- Aldose Reductase and Taurine
- Plant Molecular Biology Research
- Plant nutrient uptake and metabolism
- Plant Stress Responses and Tolerance
- Enzyme Structure and Function
- GABA and Rice Research
- Plant biochemistry and biosynthesis
- Folate and B Vitamins Research
- Plant tissue culture and regeneration
- Microbial Metabolic Engineering and Bioproduction
- Amino Acid Enzymes and Metabolism
- Lipid metabolism and biosynthesis
- Microbial Natural Products and Biosynthesis
- Plant Reproductive Biology
- Polyamine Metabolism and Applications
- Biochemical and Molecular Research
- Plant-Microbe Interactions and Immunity
- Diet, Metabolism, and Disease
- Trypanosoma species research and implications
Washington University in St. Louis
2016-2025
Kaspe (Czechia)
2020
Salk Institute for Biological Studies
1999-2019
Howard Hughes Medical Institute
2018-2019
National Statistical Institute of Portugal
2018
University of Florida
2018
Building Bridges
2016
Donald Danforth Plant Science Center
2005-2015
University of Pennsylvania
1996-2015
Milbank Memorial Fund
2011-2013
The kinetic parameters, steroid substrate specificity and identities of reaction products were determined for four homogeneous recombinant human 3α-hydroxysteroid dehydrogenase (3α-HSD) isoforms the aldo-keto reductase (AKR) superfamily. enzymes correspond to type 1 3α-HSD (AKR1C4), 2 3α(17β)-HSD (AKR1C3), 3 (AKR1C2) 20α(3α)-HSD (AKR1C1), share at least 84% amino acid sequence identity. All acted as NAD(P)(H)-dependent 3-, 17- 20-ketosteroid reductases 3α-, 17β- 20α-hydroxysteroid oxidases....
Significance Auxin is a critical plant hormone that regulates every aspect of growth and development. AUXIN RESPONSE FACTOR (ARF) transcription factors control auxin-regulated gene transcription, their activity regulated by AUXIN/INDOLE 3-ACETIC ACID repressor proteins. This work identifies dimerization the with factor insufficient to repress activity, suggesting multimerization mechanism repressing ARF transcriptional further raising possibility in other systems may play roles repression.
The aldo-keto reductases (AKRs) represent a growing oxidoreductase superfamily. Forty proteins have been identified and characterized as AKRs, an additional fourteen genes may encode related to the Found in eukaryotes prokaryotes, AKRs metabolize wide range of substrates, including aliphatic aldehydes, monosaccharides, steroids, prostaglandins, xenobiotics. This broad substrate specificity has caused problems naming these proteins. Enzymes capable reactions referred aldehyde reductase...
The kinetic parameters, steroid substrate specificity and identities of reaction products were determined for four homogeneous recombinant human 3α-hydroxysteroid dehydrogenase (3α-HSD) isoforms the aldo-keto reductase (AKR) superfamily. enzymes correspond to type 1 3α-HSD (AKR1C4), 2 3α(17β)-HSD (AKR1C3), 3 (AKR1C2) 20α(3α)-HSD (AKR1C1), share at least 84% amino acid sequence identity. All acted as NAD(P)(H)-dependent 3-, 17- 20-ketosteroid reductases 3α-, 17β- 20α-hydroxysteroid oxidases....
Chalcone synthase (CHS) catalyzes formation of the phenylpropanoid chalcone from one p-coumaroyl-CoA and three malonyl-coenzyme A (CoA) thioesters. The three-dimensional structure CHS [Ferrer, J.-L., Jez, J. M., Bowman, M. E., Dixon, R. A., Noel, P. (1999) Nat. Struct. Biol. 6, 775−784] suggests that four residues (Cys164, Phe215, His303, Asn336) participate in multiple decarboxylation condensation reactions catalyzed by this enzyme. Here, we functionally characterize 16 point mutants these...
Abstract In androgen target tissues, 3α-hydroxysteroid dehydrogenase (3α-HSD) may regulate occupancy of the receptor (AR) by catalyzing interconversion 5α-dihydrotestosterone (5α-DHT) (a potent androgen) and 3α-androstanediol weak androgen). this study, a 3α-HSD cDNA (1170 bp) was isolated from human prostate library. The prostatic encodes 323-amino acid protein with 69.9%, 84.1%, 99.4%, 87.9% sequence identity to rat liver type 1, 2, 3 3α-HSDs, respectively, is member aldo-keto reductase...
Resveratrol is a naturally occurring defense compound produced by limited number of plants in response to stresses. Besides cardiovascular benefits, this health-promoting has been reported extend life spans yeasts, flies, worms, and fish. To biosynthesize resveratrol de novo, tyrosine ammonia lyase (TAL), 4-coumarate CoA-ligase (4CL), stilbene synthase (STS) were isolated from Rhodobacter sphaeroides, Arabidopsis thaliana, Vitis vinifera, respectively. Yeast cells expressing 4CL STS produce...
In plants, cysteine biosynthesis plays a central role in fixing inorganic sulfur from the environment and provides only metabolic sulfide donor for generation of methionine, glutathione, phytochelatins, iron-sulfur clusters, vitamin cofactors, multiple secondary metabolites. O-Acetylserine sulfhydrylase (OASS) catalyzes final step biosynthesis, pyridoxal 5'-phosphate (PLP)-dependent conversion O-acetylserine into cysteine. Here we describe 2.2 A resolution crystal structure OASS Arabidopsis...
Acyl acid amido synthetases of the GH3 family act as critical prereceptor modulators plant hormone action; however, molecular basis for their selectivity is unclear. Here, we report crystal structures benzoate-specific Arabidopsis thaliana AtGH3.12/PBS3 and jasmonic acid-specific AtGH3.11/JAR1. These structures, combined with biochemical analysis, define features conjugation amino acids to diverse acyl substrates highlight importance conformational changes in carboxyl-terminal domain...
Abstract Indian mustard ( Brassica juncea L.) is known to both accumulate and tolerate high levels of heavy metals from polluted soils. To gain a comprehensive understanding the effect cadmium (Cd) treatment on B. roots, two quantitative proteomics approaches – fluorescence two‐dimensional difference gel electrophoresis (2‐D DIGE) multiplexed isobaric tagging technology (iTRAQ) were implemented. Several proteins involved in sulfur assimilation, redox homeostasis, xenobiotic detoxification...
Glutathione biosynthesis is a key component in the network of plant stress responses that counteract oxidative damage and maintain intracellular redox environment. Using combination mass spectrometry site-directed mutagenesis, we examined response Arabidopsis thaliana glutamate-cysteine ligase (GCL) to changes Mass identified two disulfide bonds (Cys186-Cys406 Cys349-Cys364) GCL. Mutation either Cys-349 or Cys-364 Ser reduced reaction rate by twofold, but substitution for Cys-186 Cys-406...
The bacterial pathogen Pseudomonas syringae modulates plant hormone signaling to promote infection and disease development. P. uses several strategies manipulate auxin physiology in Arabidopsis thaliana pathogenesis, including its synthesis of indole-3-acetic acid (IAA), the predominant form plants, production virulence factors that alter responses host; however, role pathogen-derived pathogenesis is not well understood. Here we demonstrate strain DC3000 produces IAA via a previously...
Abstract Chlorogenic acids (CGAs) are a group of phenolic secondary metabolites produced by certain plant species and an important component coffee (Coffea spp.). The CGAs have been implicated in biotic abiotic stress responses, while the related shikimate esters key intermediates for lignin biosynthesis. Here, two hydroxycinnamoyl-coenzyme A shikimate/quinate hydroxycinnamoyl transferases (HCT/HQT) from were biochemically characterized. We show, to our knowledge first time, that vitro, HCT...
Significance Plants require precise control over growth regulators during development and in their responses to biotic abiotic stresses. One strategy for modulating levels of bioactive phytohormones is conjugate these molecules amino acids using acyl acid amido synthetases the Gretchen Hagen 3 (GH3) protein family. Typically, GH3 proteins modify one type phytohormone. Structural studies, along with vitro planta biochemical analyses, reveal that GH3.5 from model plant Arabidopsis thaliana...
Chalcone isomerase (CHI) catalyzes the intramolecular cyclization of bicyclic chalcones into tricyclic (S)-flavanones. The activity CHI is essential for biosynthesis flavanone precursors floral pigments and phenylpropanoid plant defense compounds. We have examined spontaneous CHI-catalyzed reactions 4,2′,4′,6′-tetrahydroxychalcone, 4,2′,4′-trihydroxychalcone, 2′,4′-dihydroxychalcone, 4,2′-dihydroxychalcone corresponding flavanones. pH dependence formation indicates that both non-enzymatic...