A5051895571- Legume Nitrogen Fixing Symbiosis
- Nitrogen and Sulfur Effects on Brassica
- Genomics, phytochemicals, and oxidative stress
- Plant-Microbe Interactions and Immunity
- Cassava research and cyanide
- HIV/AIDS drug development and treatment
- Photosynthetic Processes and Mechanisms
- Plant Gene Expression Analysis
- Plant nutrient uptake and metabolism
- Trypanosoma species research and implications
- Plant tissue culture and regeneration
- Plant biochemistry and biosynthesis
- Enzyme Structure and Function
- Hemoglobinopathies and Related Disorders
- Plant Pathogenic Bacteria Studies
- Plant Molecular Biology Research
- Nematode management and characterization studies
- Phytase and its Applications
- Biochemical and biochemical processes
- GABA and Rice Research
- Lipid metabolism and biosynthesis
- Endoplasmic Reticulum Stress and Disease
- Microbial Natural Products and Biosynthesis
- Allelopathy and phytotoxic interactions
- RNA and protein synthesis mechanisms
Kennesaw State University
2023-2024
University of North Carolina Wilmington
2019-2023
Washington University in St. Louis
2012-2022
National Statistical Institute of Portugal
2018
European Synchrotron Radiation Facility
2012
Donald Danforth Plant Science Center
2012
European Molecular Biology Laboratory
2012
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 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...
Steviol glucosides, such as stevioside and rebaudioside A, are natural products roughly 200-fold sweeter than sugar used natural, noncaloric sweeteners. Biosynthesis of other related stevia involves formation the steviol diterpenoid followed by a series glycosylations catalyzed uridine diphosphate (UDP)-dependent glucosyltransferases. UGT76G1 from Stevia rebaudiana catalyzes branched-chain glucoside that defines molecule is critical for its high-intensity sweetness. Here, we report 3D...
The globally cultivated
In the malarial parasite Plasmodium falciparum, a multifunctional phosphoethanolamine methyltransferase (PfPMT) catalyzes methylation of (pEA) to phosphocholine for membrane biogenesis. This pathway is also found in plant and nematodes, but PMT from these organisms use multiple domains S-adenosylmethionine (AdoMet) reactions. Because PfPMT essential normal growth survival not humans, it an antiparasitic target. Here we describe 1.55 Å resolution crystal structure complex with AdoMet by...
Signaling pathways regulated by heterotrimeric G-proteins exist in all eukaryotes. The regulator of G-protein signaling (RGS) proteins are key interactors and critical modulators the Gα protein heterotrimer. However, while widespread plants, RGS have been reported to be missing from entire monocot lineage, with two exceptions. A single amino acid substitution-based adaptive coevolution Gα:RGS was proposed enable loss monocots. We used a combination evolutionary biochemical analyses homology...
Heterotrimeric GTP-binding protein alpha subunit (Gα) and its cognate regulator of G-protein signaling (RGS) transduce signals in eukaryotes spanning protists, amoeba, animals, fungi, plants. The core catalytic mechanisms the GTPase activity Gα interaction interface with RGS for acceleration GTP hydrolysis seem to be conserved across these groups; however, gene is under low selective pressure plants, resulting frequent loss. Our current understanding structural basis Gα:RGS regulation plants...
The reconstitution of biosynthetic pathways in heterologous hosts is often challenged by the switch to a foreign cellular environment, lacking compatible structural or regulatory features. Auxiliary non-catalytic proteins can play critical role modulating metabolic flux and pathway efficiency. Chalcone isomerase-like (CHIL) protein known serve as partner chalcone synthase (CHS) flavonoid biosynthesis, rectifying its promiscuous activity preventing by-product formation, such aberrant p...
Serine acetyltransferase (SAT) catalyzes the limiting reaction in plant and microbial biosynthesis of cysteine. In addition to its enzymatic function, SAT forms a macromolecular complex with O-acetylserine sulfhydrylase. Formation cysteine regulatory (CRC) is critical biochemical control feature sulfur metabolism. Here we present 1.75-3.0 Å resolution x-ray crystal structures soybean (Glycine max) (GmSAT) apoenzyme, serine-bound, CoA-bound forms. The GmSAT-serine GmSAT-CoA provide new...
The nonoxidative decarboxylation of aromatic acids occurs in a range microbes and is interest for bioprocessing metabolic engineering. Although phenolic acid decarboxylases provide useful tools bioindustrial applications, the molecular bases how these enzymes function are only beginning to be examined. Here we present 2.35-Å-resolution X-ray crystal structure ferulic decarboxylase (FDC1; UbiD) from Saccharomyces cerevisiae. FDC1 shares structural similarity with UbiD family that involved...
Metabolic engineering approaches are increasingly employed for environmental applications. Because phytochelatins (PC) protect plants from heavy metal toxicity, strategies directed at manipulating the biosynthesis of these peptides hold promise remediation soils and groundwaters contaminated with metals. Directed evolution Arabidopsis thaliana phytochelatin synthase (AtPCS1) yields mutants that confer levels cadmium tolerance accumulation greater than expression wild-type enzyme in...
The symbiosis between rhizobial microbes and host plants involves the coordinated expression of multiple genes, which leads to nodule formation nitrogen fixation. As part transcriptional machinery for nodulation across a range Rhizobium, NolR serves as global regulatory protein. Here, we present X-ray crystal structures in unliganded form complexed with two different 22-base pair (bp) double-stranded operator sequences (oligos AT AA). Structural biochemical analysis reveals protein-DNA...
JIB-04, a specific inhibitor of the O2-activating, Fe-dependent histone lysine demethylases, is revealed to disrupt binding O2 in KDM4A/JMJD2A through continuous O2-consumption assay, X-ray crystal structure data, and molecular docking.
Abstract Aldehyde dehydrogenases (ALDHs) catalyze the conversion of various aliphatic and aromatic aldehydes into corresponding carboxylic acids. Traditionally considered as housekeeping enzymes, new biochemical roles are being identified for members ALDH family. Recent work showed that AldA from plant pathogen Pseudomonas syringae strain PtoDC3000 (PtoDC3000) functions an indole-3-acetaldehyde dehydrogenase synthesis indole-3-acetic acid (IAA). IAA produced by allows to suppress salicylic...
In plants, sulfur must be obtained from the environment and assimilated into usable forms for metabolism. ATP sulfurylase catalyses thermodynamically unfavourable formation of a mixed phosphosulfate anhydride in APS (adenosine 5'-phosphosulfate) sulfate as first committed step assimilation plants. contrast to multi-functional, allosterically regulated sulfurylases bacteria, fungi mammals, plant enzyme functions mono-functional, non-allosteric homodimer. Owing these differences, here we...
Phosphocholine (pCho) is a precursor for phosphatidylcholine and osmoprotectants in plants. In plants, de novo synthesis of pCho relies on the phosphobase methylation pathway. Phosphoethanolamine methyltransferase (PMT) catalyzes triple phosphoethanolamine (pEA) to pCho. The plant PMTs are di-domain methyltransferases that divide pEA one domain from subsequent methylations second domain. To understand molecular basis this architecture, we examined biochemical properties three Arabidopsis...