A5030927509- Plant Molecular Biology Research
- Bacterial Genetics and Biotechnology
- Plant nutrient uptake and metabolism
- Photosynthetic Processes and Mechanisms
- Nitrogen and Sulfur Effects on Brassica
- Antimicrobial Peptides and Activities
- GABA and Rice Research
- Escherichia coli research studies
- Bacteriophages and microbial interactions
- Antimicrobial agents and applications
- Plant Reproductive Biology
- Plant Parasitism and Resistance
- Plant Stress Responses and Tolerance
- Soybean genetics and cultivation
- Plant biochemistry and biosynthesis
- Genomics, phytochemicals, and oxidative stress
- Bacterial biofilms and quorum sensing
- Crystallization and Solubility Studies
- Plant Gene Expression Analysis
- Cellular transport and secretion
- Protein Structure and Dynamics
- Crystallography and molecular interactions
- Inorganic Fluorides and Related Compounds
- Advanced NMR Techniques and Applications
- Plant-Microbe Interactions and Immunity
Washington University in St. Louis
2012-2021
University of Missouri–St. Louis
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.
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...
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...
The antimicrobial triclosan is used in a wide range of consumer products ranging from toothpaste, cleansers, socks, and baby toys. A bacteriostatic inhibitor fatty acid synthesis, extremely stable accumulates the environment. Approximately 75% adults United States have detectable levels compound their urine, with sizeable fraction individuals (>10%) having urine concentrations equal to or greater than minimal inhibitory concentration for
Plants respond to developmental cues and environmental stresses by controlling both the level activity of various hormones. One mechanism modulating hormone action involves amino acid conjugation. In plants, GH3 family enzymes conjugates acids jasmonates, auxins, benzoates. The effect conjugation can lead activation, inactivation, or degradation these molecules. Although acyl specificities a few have been examined qualitatively, further in-depth analysis structure function proteins is needed...
Significance Bacterial cells constantly face nutrient fluctuations in their natural environments. While previous studies have identified gene expression changes upon depletion, much less well known is how cellular morphology and cytoplasmic properties respond to shifts availability. Here, we discovered that rapid switching of fast-growing Escherichia coli nutrient-free conditions results substantial shrinkage the inner membrane away from cell wall, especially at new pole. Shrinkage was...
Bacterial morphology is a complex trait that highly sensitive to changes in the environment. For heterotrophic organisms, such as Escherichia coli, increases nutrient levels are frequently accompanied by several-fold both size and growth rate. Despite dramatic nature of these changes, how alterations availability translate into remains largely open question. To understand signaling networks coupling with shape, we examined impact deletions entirety non-essential central carbon metabolic...
Cell size is a complex trait, derived from both genetic and environmental factors. Environmental determinants of bacterial cell identified to date primarily target assembly cytosolic components the division machinery. Whether certain cues also impact through changes in or activity extracytoplasmic proteins remains an open question. Here, we identify extracellular pH as modulator significant determinant across evolutionarily distant species. In Gram-negative model organism Escherichia coli,...
The combination of protein crystallography and small-angle X-ray scattering (SAXS) provides a powerful method to investigate changes in conformation. These complementary structural techniques were used probe the solution structure apo ligand-bound forms Arabidopsis thaliana acyl acid-amido synthetase GH3.12. This enzyme is part extensive GH3 family plays critical role regulation plant hormones through formation amino-acid-conjugated hormone products via an ATP-dependent reaction mechanism....
Heterotrimeric G-proteins and the regulator of G-protein signaling (RGS) proteins, which accelerate inherent GTPase activity Gα are common in animals encoded by large gene families; however, plants is thought to be more limited scope. For example, Arabidopsis thaliana contains one Gα, Gβ, three Gγ, RGS protein. Recent examination Glycine max (soybean) genome reveals a larger set G-protein-related genes raises possibility intricate networks than previously observed plants. Stopped-flow...
The epidermal growth factor (EGF) receptor is a member of the ErbB family receptors that also includes ErbB2, ErbB3, and ErbB4. These form homo- heterodimers in response to ligand with ErbB2 being preferred dimerization partner. Here we use (125)I-EGF binding quantitate interaction EGF ErbB2. We show EGFR/ErbB2 heterodimer binds 7-fold higher affinity than EGFR homodimer. Because it cannot bind second ligand, not subject ligand-induced dissociation caused by negatively cooperative site on...
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...
Adenosine 5′-phosphosulfate kinase (APSK) catalyzes the phosphorylation of adenosine (APS) to 3′-phosphoadenosine-5′-phosphosulfate (PAPS). Crystallographic studies APSK from Arabidopsis thaliana revealed presence a regulatory intersubunit disulfide bond (Cys86–Cys119). The reduced enzyme displayed improved catalytic efficiency and decreased effectiveness substrate inhibition by APS compared with oxidized form. Here we examine effect formation role N-terminal domain on nucleotide binding...
Legume root nodules develop as a result of symbiotic relationship between the plant and nitrogen-fixing rhizobia bacteria in soil. Auxin activity is detected different cell types at stages nodule development; well an enhanced sensitivity to auxin inhibits, which could affect development. While some transport signaling mechanisms that achieve precise spatiotemporal output are known, role metabolism during development unclear. Using soybean lateral organ transcriptome data set, we identified...
Regulator of G-protein signaling (RGS) proteins are a family highly diverse, multifunctional that function primarily as GTPase accelerating (GAPs). RGS increase the rate GTP hydrolysis by Gα and essentially regulate duration active signaling. Recently, we have identified two chimeric from soybean reported their distinct GAP activities on individual proteins. A single amino acid substitution (Alanine 357 to Valine) RGS2 is responsible for differential activity. Surprisingly, most monocot...